The Great Oxidation Event (GOE) or Great Oxygenation Event, also called the Oxygen Catastrophe, Oxygen Revolution, Oxygen Crisis or Oxygen Holocaust, was a time interval during the Early Earth's Paleoproterozoic Era when the Earth's atmosphere and the shallow ocean first experienced a rise in the concentration of oxygen. This began approximately 2.460–2.426 Ga (billion years) ago, during the Siderian period, and ended approximately 2.060 Ga, during the Rhyacian. Geological, isotopic, and chemical evidence suggests that biologically-produced molecular oxygen (dioxygen or O2) started to accumulate in Earth's atmosphere and changed it from a weakly reducing atmosphere practically devoid of oxygen into an oxidizing one containing abundant free oxygen, with oxygen levels being as high as 10% of their present atmospheric level by the end of the GOE.

The sudden injection of highly reactive free oxygen, toxic to the then-mostly anaerobic biosphere, may have caused the extinction of many existing organisms on Earth — then mostly archaeal colonies that used retinal to utilize green-spectrum light energy and power a form of anoxygenic photosynthesis (see Purple Earth hypothesis). Although the event is inferred to have constituted a mass extinction, due in part to the great difficulty in surveying microscopic organisms' abundances, and in part to the extreme age of fossil remains from that time, the Great Oxidation Event is typically not counted among conventional lists of "great extinctions", which are implicitly limited to the Phanerozoic eon. In any case, Isotope geochemistry data from sulfate minerals have been interpreted to indicate a decrease in the size of the biosphere of >80% associated with changes in nutrient supplies at the end of the GOE.

The GOE is inferred to have been caused by cyanobacteria who evolved porphyrin-based photosynthesis, which produces dioxygen as a byproduct. The increasing oxygen level eventually depleted the reducing capacity of ferrous compounds, hydrogen sulfide and atmospheric methane, and compounded by a global glaciation, devastated the microbial mats around the Earth's surface. The subsequent adaptation of surviving archaea via symbiogenesis with aerobic proteobacteria (which went endosymbiont and became mitochondria) may have led to the rise of eukaryotic organisms and the subsequent evolution of multicellular life-forms.

The early atmosphere

The composition of the Earth's earliest atmosphere is not known with certainty. However, the bulk was likely nitrogen, , and carbon dioxide, , which are also the predominant nitrogen- and carbon-bearing gases produced by volcanism today. These are relatively inert gases. Oxygen, , meanwhile, was present in the atmosphere at just 0.001% of its present atmospheric level. The Sun shone at about 70% of its current brightness 4 billion years ago, but there is strong evidence that liquid water existed on Earth at the time. A warm Earth, in spite of a faint Sun, is known as the faint young Sun paradox. Either carbon dioxide levels were much higher at the time, providing enough of a greenhouse effect to warm the Earth, or other greenhouse gases were present. The most likely such gas is methane, , which is a powerful greenhouse gas and was produced by early forms of life known as methanogens. Scientists continue to research how the Earth was warmed before life arose.

An atmosphere of  and  with trace amounts of , , carbon monoxide (), and hydrogen (), is described as a weakly reducing atmosphere. Such an atmosphere contains practically no oxygen. The modern atmosphere contains abundant oxygen, making it an oxidizing atmosphere. The rise in oxygen is attributed to photosynthesis by cyanobacteria, which are thought to have evolved as early as 3.5 billion years ago.

The current scientific understanding of when and how the Earth's atmosphere changed from a weakly reducing to a strongly oxidizing atmosphere largely began with the work of the American geologist Preston Cloud in the 1970s. Cloud observed that detrital sediments older than about 2 billion years ago contained grains of pyrite, uraninite, and siderite, all minerals containing reduced forms of iron or uranium that are not found in younger sediments because they are rapidly oxidized in an oxidizing atmosphere. He further observed that continental red beds, which get their color from the oxidized (ferric) mineral hematite, began to appear in the geological record at about this time. Banded iron formation largely disappears from the geological record at 1.85 billion years ago, after peaking at about 2.5 billion years ago. Banded iron formation can form only when abundant dissolved ferrous iron is transported into depositional basins, and an oxygenated ocean blocks such transport by oxidizing the iron to form insoluble ferric iron compounds. The end of the deposition of banded iron formation at 1.85 billion years ago is therefore interpreted as marking the oxygenation of the deep ocean. Heinrich Holland further elaborated these ideas through the 1980s, placing the main time interval of oxygenation between 2.2 and 1.9 billion years ago, and they continue to shape the current scientific understanding.

Constraining the onset of atmospheric oxygenation has proven particularly challenging for geologists and geochemists. While there is a widespread consensus that initial oxygenation of the atmosphere happened sometime during the first half of the Paleoproterozoic, there is disagreement on the exact timing of this event. Scientific publications between 2016 and 2022 have differed in the inferred timing of the onset of atmospheric oxygenation by approximately 500 million years; estimates of 2.7 Ga, 2.501-2.434 Ga 2.501-2.225 Ga, 2.460-2.426 Ga, 2.430 Ga, and 2.33 Ga have been given. This is in large part due to an incomplete sedimentary record for the Paleoproterozoic (e.g., because of subduction and metamorphism), uncertainties in depositional ages for many ancient sedimentary units, and uncertainties related to the interpretation of different geological/geochemical proxies. While the effects of an incomplete geological record have been discussed and quantified in the field of paleontology for several decades, particularly with respect to the evolution and extinction of organisms (the Signor-Lipps Effect), this is rarely quantified when considering geochemical records, and may therefore lead to uncertainties for scientists studying the timing of atmospheric oxygenation.

Geological evidence
Evidence for the Great Oxidation Event is provided by a variety of petrological and geochemical markers that define this geological event.

Continental indicators
Paleosols, detrital grains, and red beds are evidence of low oxygen levels. Paleosols (fossil soils) older than 2.4 billion years old have low iron concentrations that suggest anoxic weathering. Detrital grains composed of pyrite, siderite, and uraninite (redox-sensitive detrital minerals) are found in sediments older than ca. 2.4 Ga. These minerals are only stable under low oxygen conditions, and so their occurrence as detrital minerals in fluvial and deltaic sediments are widely interpreted as evidence of an anoxic atmosphere. In contrast to redox-sensitive detrital minerals are red beds, red-colored sandstones that are coated with hematite. The occurrence of red beds indicates that there was sufficient oxygen to oxidize iron to its ferric state, and represent a marked contrast to sandstones deposited under anoxic conditions which are often beige, white, grey, or green.

Banded iron formation (BIF)

Banded iron formations are composed of thin alternating layers of chert (a fine-grained form of silica) and iron oxides, magnetite and hematite. Extensive deposits of this rock type are found around the world, almost all of which are more than 1.85 billion years old and most of which were deposited around 2.5 billion years ago. The iron in banded iron formations is partially oxidized, with roughly equal amounts of ferrous and ferric iron. Deposition of a banded iron formation requires both an anoxic deep ocean capable of transporting iron in soluble ferrous form, and an oxidized shallow ocean where the ferrous iron is oxidized to insoluble ferric iron and precipitates onto the ocean floor. The deposition of banded iron formations before 1.8 billion years ago suggests the ocean was in a persistent ferruginous state, but deposition was episodic and there may have been significant intervals of euxinia. The transition from deposition of banded iron formations to manganese oxides in some strata has been considered a key tipping point in the timing of the GOE because it is believed to indicate the escape of significant molecular oxygen into the atmosphere in the absence of ferrous iron as a reducing agent.

Iron speciation
Black laminated shales, rich in organic matter, are often regarded as a marker for anoxic conditions. However, the deposition of abundant organic matter is not a sure indication of anoxia, and burrowing organisms that destroy lamination had not yet evolved during the time frame of the Great Oxygenation Event. Thus laminated black shale by itself is a poor indicator of oxygen levels. Scientists must look instead for geochemical evidence of anoxic conditions. These include ferruginous anoxia, in which dissolved ferrous iron is abundant, and euxinia, in which hydrogen sulfide is present in the water.

Examples of such indicators of anoxic conditions include the degree of pyritization (DOP), which is the ratio of iron present as pyrite to the total reactive iron. Reactive iron, in turn, is defined as iron found in oxides and oxyhydroxides, carbonates, and reduced sulfur minerals such as pyrites, in contrast with iron tightly bound in silicate minerals. A DOP near zero indicates oxidizing conditions, while a DOP near 1 indicates euxinic conditions. Values of 0.3 to 0.5 are transitional, suggesting anoxic bottom mud under an oxygenated ocean. Studies of the Black Sea, which is considered a modern model for ancient anoxic ocean basins, indicate that high DOP, a high ratio of reactive iron to total iron, and a high ratio of total iron to aluminum are all indicators of transport of iron into a euxinic environment. Ferruginous anoxic conditions can be distinguished from euxenic conditions by a DOP less than about 0.7.

The currently available evidence suggests that the deep ocean remained anoxic and ferruginous as late as 580 million years ago, well after the Great Oxygenation Event, remaining just short of euxenic during much of this interval of time. Deposition of banded iron formation ceased when conditions of local euxenia on continental platforms and shelves began precipitating iron out of upwelling ferruginous water as pyrite.

Isotopes
Some of the most persuasive evidence for the Great Oxidation Event is provided by the mass-independent fractionation (MIF) of sulfur. The chemical signature of the MIF of sulfur is found prior to 2.4–2.3 billion years ago but disappears thereafter. The presence of this signature all but eliminates the possibility of an oxygenated atmosphere.

Different isotopes of a chemical element have slightly different atomic masses. Most of the differences in geochemistry between isotopes of the same element scale with this mass difference. These include small differences in molecular velocities and diffusion rates, which are described as mass-dependent fractionation processes. By contrast, mass-independent fractionation describes processes that are not proportional to the difference in mass between isotopes. The only such process likely to be significant in the geochemistry of sulfur is photodissociation. This is the process in which a molecule containing sulfur is broken up by solar ultraviolet (UV) radiation. The presence of a clear MIF signature for sulfur prior to 2.4 billion years ago shows that UV radiation was penetrating deep into the Earth's atmosphere. This in turn rules out an atmosphere containing more than traces of oxygen, which would have produced an ozone layer that shielded the lower atmosphere from UV radiation. The disappearance of the MIF signature for sulfur indicates the formation of such an ozone shield as oxygen began to accumulate in the atmosphere. Mass-dependent fractionation of sulphur also indicates the presence of oxygen in that oxygen is required to facilitate repeated redox cycling of sulphur.

Mass-dependent fractionation also provides clues to the Great Oxygenation Event. For example, oxidation of manganese in surface rocks by atmospheric oxygen leads to further reactions that oxidize chromium. The heavier 53Cr is oxidized preferentially over the lighter 52Cr, and the soluble oxidized chromium carried into the ocean shows this enhancement of the heavier isotope. The chromium isotope ratio in banded iron formation suggests small but significant quantities of oxygen in the atmosphere before the Great Oxidation Event, and a brief return to low oxygen abundance 500 million years after the Great Oxidation Event. However, the chromium data may conflict with the sulfur isotope data, which calls the reliability of the chromium data into question. It is also possible that oxygen was present earlier only in localized "oxygen oases". Since chromium is not easily dissolved, its release from rocks requires the presence of a powerful acid such as sulfuric acid (H2SO4) which may have formed through bacterial oxidation of pyrite. This could provide some of the earliest evidence of oxygen-breathing life on land surfaces.

Other elements whose mass-dependent fractionation may provide clues to the Great Oxidation Event include carbon, nitrogen, transitional metals such as molybdenum and iron, and non-metal elements such as selenium.

Fossils and biomarkers (chemical fossils)

While the Great Oxidation Event is generally thought to be a result of oxygenic photosynthesis by ancestral cyanobacteria, the presence of cyanobacteria in the Archaean before the Great Oxidation Event is a highly controversial topic. Structures that are claimed to be fossils of cyanobacteria exist in rock as old as 3.5 billion years old. These include microfossils of supposedly cyanobacterial cells and macrofossils called stromatolites, which are interpreted as colonies of microbes, including cyanobacteria, with characteristic layered structures. Modern stromatolites, which can only be seen in harsh environments such as Shark Bay in Western Australia, are associated with cyanobacteria and thus fossil stromatolites had long been interpreted as the evidence for cyanobacteria. However, it has increasingly been inferred that at least some of these Archaean fossils were generated abiotically or produced by non-cyanobacterial phototrophic bacteria.

Additionally, Archaean sedimentary rocks were once found to contain biomarkers, also known as chemical fossils, interpreted as fossilized membrane lipids from cyanobacteria and eukaryotes. For example, traces of 2α-methylhopanes and steranes that are thought to be derived from cyanobacteria and eukaryotes, respectively, were found in the Pilbara of Western Australia. Steranes are diagenetic products of sterols, which are biosynthesized utilizing molecular oxygen. Thus, steranes can additionally serve as an indicator of oxygen in the atmosphere. However, these biomarker samples have since been shown to have been contaminated and so the results are no longer accepted.

Other indicators
Some elements in marine sediments are sensitive to different levels of oxygen in the environment such as the transition metals molybdenum and rhenium. Non-metal elements such as selenium and iodine are also indicators of oxygen levels.

Hypotheses

The ability to generate oxygen via photosynthesis likely first appeared in the ancestors of cyanobacteria. These organisms evolved at least 2.45–2.32 billion years ago, and probably as early as 2.7 billion years ago or earlier. However, oxygen remained scarce in the atmosphere until around 2.0 billion years ago, and banded iron formation continued to be deposited until around 1.85 billion years ago. Given the rapid multiplication rate of cyanobacteria under ideal conditions, an explanation is needed for the delay of at least 400 million years between the evolution of oxygen-producing photosynthesis and the appearance of significant oxygen in the atmosphere.

Hypotheses to explain this gap must take into consideration the balance between oxygen sources and oxygen sinks. Oxygenic photosynthesis produces organic carbon that must be segregated from oxygen to allow oxygen accumulation in the surface environment, otherwise the oxygen back-reacts with the organic carbon and does not accumulate. The burial of organic carbon, sulfide, and minerals containing ferrous iron (Fe) is a primary factor in oxygen accumulation. When organic carbon is buried without being oxidized, the oxygen is left in the atmosphere. In total, the burial of organic carbon and pyrite today creates   of O per year. This creates a net O flux from the global oxygen sources.

The rate of change of oxygen can be calculated from the difference between global sources and sinks. The oxygen sinks include reduced gases and minerals from volcanoes, metamorphism and weathering. The GOE started after these oxygen-sink fluxes and reduced-gas fluxes were exceeded by the flux of O2 associated with the burial of reductants, such as organic carbon. For the weathering mechanisms,  of O per year today goes to the sinks composed of reduced minerals and gases from volcanoes, metamorphism, percolating seawater and heat vents from the seafloor. On the other hand,  of O per year today oxidizes reduced gases in the atmosphere through photochemical reaction. On the early Earth, there was visibly very little oxidative weathering of continents (e.g., a lack of red beds) and so the weathering sink on oxygen would have been negligible compared to that from reduced gases and dissolved iron in oceans.

Dissolved iron in oceans exemplifies O2 sinks. Free oxygen produced during this time was chemically captured by dissolved iron, converting iron Fe and Fe2+ to magnetite () that is insoluble in water, and sank to the bottom of the shallow seas to create banded iron formations such as the ones found in Minnesota and the Pilbara of Western Australia. It took 50 million years or longer to deplete the oxygen sinks. The rate of photosynthesis and associated rate of organic burial also affect the rate of oxygen accumulation. When land plants spread over the continents in the Devonian, more organic carbon was buried and likely allowed higher O2 levels to occur. Today, the average time that an O molecule spends in the air before it is consumed by geological sinks is about 2 million years. That residence time is relatively short in geologic time; so in the Phanerozoic, there must have been feedback processes that kept the atmospheric O level within bounds suitable for animal life.

Evolution by stages
Preston Cloud originally proposed that the first cyanobacteria had evolved the capacity to carry out oxygen-producing photosynthesis but had not yet evolved enzymes (such as superoxide dismutase) for living in an oxygenated environment. These cyanobacteria would have been protected from their own poisonous oxygen waste through its rapid removal via the high levels of reduced ferrous iron, Fe(II), in the early ocean. He suggested that the oxygen released by photosynthesis oxidized the Fe(II) to ferric iron, Fe(III), which precipitated out of the sea water to form banded iron formation. He interpreted the great peak in deposition of banded iron formation at the end of the Archean as the signature for the evolution of mechanisms for living with oxygen. This ended self-poisoning and produced a population explosion in the cyanobacteria that rapidly oxygenated the ocean and ended banded iron formation deposition. However, improved dating of Precambrian strata showed that the late Archean peak of deposition was spread out over tens of millions of years, rather than taking place in a very short interval of time following the evolution of oxygen-coping mechanisms. This made Cloud's hypothesis untenable. Most modern interpretations describe the GOE as a long, protracted process that took place over hundreds of millions of years rather than a single abrupt event, with the quantity of atmospheric oxygen fluctuating in relation to the capacity of oxygen sinks and the productivity of oxygenic photosynthesisers over the course of the GOE.

More recently, families of bacteria have been discovered that closely resemble cyanobacteria but show no indication of ever having possessed photosynthetic capability. These may be descended from the earliest ancestors of cyanobacteria, which only later acquired photosynthetic ability by lateral gene transfer. Based on molecular clock data, the evolution of oxygen-producing photosynthesis may have occurred much later than previously thought, at around 2.5 billion years ago. This reduces the gap between the evolution of oxygen photosynthesis and the appearance of significant atmospheric oxygen.

Nutrient famines
A second possibility is that early cyanobacteria were starved for vital nutrients, and this checked their growth. However, a lack of the scarcest nutrients, iron, nitrogen, and phosphorus, could have slowed, but not prevented, a cyanobacteria population explosion and rapid oxygenation. The explanation for the delay in the oxygenation of the atmosphere following the evolution of oxygen-producing photosynthesis likely lies in the presence of various oxygen sinks on the young Earth.

Nickel famine
Early chemosynthetic organisms likely produced methane, an important trap for molecular oxygen, since methane readily oxidizes to carbon dioxide (CO2) and water in the presence of UV radiation. Modern methanogens require nickel as an enzyme cofactor. As the Earth's crust cooled and the supply of volcanic nickel dwindled, oxygen-producing algae began to outperform methane producers, and the oxygen percentage of the atmosphere steadily increased. From 2.7 to 2.4 billion years ago, the rate of deposition of nickel declined steadily from a level 400 times today's. This nickel famine was somewhat buffered by an uptick in sulfide weathering at the start of the GOE that brought some nickel to the oceans, without which methanogenic organisms would have declined in abundance  more precipitously, plunging Earth into even more severe and long-lasting icehouse conditions than those seen during the Huronian glaciation.

Increasing flux
One hypothesis argues that the GOE was the immediate result of photosynthesis, although the majority of scientists suggest that a long-term increase of oxygen is more likely. Several model results show possibilities of long-term increase of carbon burial, but the conclusions are indeterminate.

Decreasing sink
In contrast to the increasing flux hypothesis, there are several hypotheses that attempt to use decrease of sinks to explain the GOE. One theory suggests that the composition of the volatiles from volcanic gases was more oxidized. Another theory suggests that the decrease of metamorphic gases and serpentinization is the main key of GOE. Hydrogen and methane released from metamorphic processes are also lost from Earth's atmosphere over time and leave the crust oxidized. Scientists realized that hydrogen would escape into space through a process called methane photolysis, in which methane decomposes under the action of ultraviolet light in the upper atmosphere and releases its hydrogen. The escape of hydrogen from the Earth into space must have oxidized the Earth because the process of hydrogen loss is chemical oxidation. This process of hydrogen escape required the generation of methane by methanogens, so that methanogens actually helped create the conditions necessary for the oxidation of the atmosphere.

Tectonic trigger

One hypothesis suggests that the oxygen increase had to await tectonically driven changes in the Earth, including the appearance of shelf seas, where reduced organic carbon could reach the sediments and be buried. The burial of reduced carbon as graphite or diamond around subduction zones released molecular oxygen into the atmosphere. The appearance of oxidised magmas enriched in sulphur formed around subduction zones confirms changes in tectonic regime played an important role in the oxygenation of Earth's atmosphere. The newly produced oxygen was first consumed in various chemical reactions in the oceans, primarily with iron. Evidence is found in older rocks that contain massive banded iron formations apparently laid down as this iron and oxygen first combined; most present-day iron ore lies in these deposits. It was assumed oxygen released from cyanobacteria resulted in the chemical reactions that created rust, but it appears the iron formations were caused by anoxygenic phototrophic iron-oxidizing bacteria, which does not require oxygen. Evidence suggests oxygen levels spiked each time smaller land masses collided to form a super-continent. Tectonic pressure thrust up mountain chains, which eroded releasing nutrients into the ocean that fed photosynthetic cyanobacteria.

Bistability
Another hypothesis posits a model of the atmosphere that exhibits bistability: two steady states of oxygen concentration. The state of stable low oxygen concentration (0.02%) experiences a high rate of methane oxidation. If some event raises oxygen levels beyond a moderate threshold, the formation of an ozone layer shields UV rays and decreases methane oxidation, raising oxygen further to a stable state of 21% or more. The Great Oxygenation Event can then be understood as a transition from the lower to the upper steady states.

Increasing photoperiod
Cyanobacteria tend to consume nearly as much oxygen at night as they produce during the day. However, experiments demonstrate that cyanobacterial mats produce a greater excess of oxygen with longer photoperiods. The rotational period of the Earth was only about six hours shortly after its formation, 4.5 billion years ago, but increased to 21 hours by 2.4 billion years ago, in the Paleoproterozoic. The rotational period increased again, starting 700 million years ago, to its present value of 24 hours. The total amount of oxygen produced by the cyanobacteria remained the same with longer days, but the longer day, the more time oxygen has to diffuse into the water.

Consequences of oxygenation

Eventually, oxygen started to accumulate in the atmosphere, with two major consequences.
 Oxygen likely oxidized atmospheric methane (a strong greenhouse gas) to carbon dioxide (a weaker one) and water. This weakened the greenhouse effect of the Earth's atmosphere, causing planetary cooling, which has been proposed to have triggered a series of ice ages known as the Huronian glaciation, bracketing an age range of 2.45–2.22 billion years ago.
 The increased oxygen concentrations provided a new opportunity for biological diversification, as well as tremendous changes in the nature of chemical interactions between rocks, sand, clay, and other geological substrates and the Earth's air, oceans, and other surface waters. Despite the natural recycling of organic matter, life had remained energetically limited until the widespread availability of oxygen. The availability of oxygen greatly increased the free energy available to living organisms, with global environmental impacts. For example, mitochondria evolved after the GOE, giving organisms the energy to exploit new, more complex morphologies interacting in increasingly complex ecosystems, although these did not appear until the late Proterozoic and Cambrian.

Role in mineral diversification

The Great Oxygenation Event triggered an explosive growth in the diversity of minerals, with many elements occurring in one or more oxidized forms near the Earth's surface. It is estimated that the GOE was directly responsible for more than 2,500 of the total of about 4,500 minerals found on Earth today. Most of these new minerals were formed as hydrated and oxidized forms due to dynamic mantle and crust processes.

Role in cyanobacteria evolution
In field studies done in Lake Fryxell, Antarctica, scientists found that mats of oxygen-producing cyanobacteria produced a thin layer, one to two millimeters thick, of oxygenated water in an otherwise anoxic environment, even under thick ice. By inference, these organisms could have adapted to oxygen even before oxygen accumulated in the atmosphere. The evolution of such oxygen-dependent organisms eventually established an equilibrium in the availability of oxygen, which became a major constituent of the atmosphere.

Origin of eukaryotes
It has been proposed that a local rise in oxygen levels due to cyanobacterial photosynthesis in ancient microenvironments was highly toxic to the surrounding biota, and that this selective pressure drove the evolutionary transformation of an archaeal lineage into the first eukaryotes.  Oxidative stress involving production of reactive oxygen species (ROS) might have acted in synergy with other environmental stresses (such as ultraviolet radiation and/or desiccation) to drive selection in an early archaeal lineage towards eukaryosis.  This archaeal ancestor may already have had DNA repair mechanisms based on DNA pairing and recombination and possibly some kind of cell fusion mechanism. The detrimental effects of internal ROS (produced by endosymbiont proto-mitochondria) on the archaeal genome could have promoted the evolution of meiotic sex from these humble beginnings. Selective pressure for efficient DNA repair of oxidative DNA damage may have driven the evolution of eukaryotic sex involving such features as cell-cell fusions, cytoskeleton-mediated chromosome movements and emergence of the nuclear membrane. Thus the evolution of eukaryotic sex and eukaryogenesis were likely inseparable processes that evolved in large part to facilitate DNA repair. The evolution of mitochondria, which are well suited for oxygenated environments, may have occurred during the GOE.

However, other authors express scepticism that the GOE resulted in widespread eukaryotic diversification due to the lack of robust evidence, concluding that the oxygenation of the oceans and atmosphere does not necessarily lead to increases in ecological and physiological diversity.

Lomagundi-Jatuli event
The rise in oxygen content was not linear: instead, there was a rise in oxygen content around 2.3 Ga ago, followed by a drop around 2.1 Ga ago. This rise in oxygen is called the Lomagundi-Jatuli event (LJE) or Lomagundi event, (named for a district of Southern Rhodesia) and the time period has been termed Jatulian; it is currently considered to be part of the Rhyacian period. During the Lomagundi-Jatuli event, oxygen amounts in the atmosphere reached similar heights to modern levels, before returning to low levels during the following stage, which caused the deposition of black shales (rocks that contain large amounts of organic matter that would otherwise have been burned away by oxygen). This drop in oxygen levels is called the . Evidence for the event has been found globally: in Fennoscandia and northern Russia, Scotland, Ukraine, China, the Wyoming Craton in North America, Brazil, Uruguay, Gabon, Zimbabwe, South Africa, India, and Australia. Oceans seem to have stayed rich in oxygen for some time even after the event itself ended.

It has been hypothesized that eukaryotes first evolved during the Lomagundi-Jatuli event.

See also
 Boring Billion – Earth history between 1.8 and 0.8 billion years ago, characterized by tectonic stability, climatic stasis, and a slow biological evolution with very low oxygen levels and no evidence of glaciation
 Geological history of oxygen – Timeline of the development of free oxygen in the Earth's oceans and atmosphere

 Purple Earth hypothesis – Hypothesis that early photosynthesis reflected purple light
 Rare Earth hypothesis – Hypothesis that complex extraterrestrial life is an extremely rare phenomenon

References

External links

Paleoproterozoic
Origin of life
Oxygen
Events in the geological history of Earth
Evolution of the biosphere
Extinction events
Mass extinction timelines
Meteorological hypotheses

Great Oxidation Event


Fort Crook was a U. S. Army post, first established as Camp Hollenbush in 1857, in Shasta County, California, northeast of Fall River Mills, California.

The Fort Crook Museum covers its history.

History
Camp Hollenbush was established by Captain John W.T. Gardiner commanding a detachment of soldiers from the 1st U.S. Dragoons and the 4th U.S. Infantry.  The post was named for Assistant Surgeon Calvin G. Hollenbush.
The post was later renamed Fort Crook for 1st Lieutenant George Crook, of the 4th U.S. Infantry, who commanded the Pitt River Expedition of 1857 and in one of the several engagements was severely wounded by an Indian arrow.

During the American Civil War California Volunteers garrisoned the post.
From August 3–12, 1861, troops from this post made a Scout from Fort Crook to Round Valley, in Mendocino County

On August 5, 1861, other troops of the garrison fought a Skirmish in the Upper Pit River Valley with the Achomawi.  On August 15–22, 1861 they conducted the Expedition from Fort Crook to the Pit River during which they fought a skirmish near Kellogg's Lake on August 19.

The U. S. Army abandoned the post in 1869.  The land was returned to the public domain in 1881.

The Location Today
There are no remains at the original site.  On November 11, 1934 the Fort Crook Historical Society, placed a historical marker for Fort Crook, in Fall River Mills at .  A restored cabin from the fort site was subsequently located at the Fort Crook Museum in Fall River Mills, California at the east intersection of McArthur Road & Soldier Mountain Road near the marker.

In 2009, a round barn that was used in breaking and training wild horses for the U.S. Army was reconstructed on the grounds of the Fort Crook Museum.

References

External links
 Fort Crook Museum

Crook (California)
History of Shasta County, California
California Historical Landmarks
Closed installations of the United States Army
California in the American Civil War
American Civil War army posts
Fort Crook (California)
1857 establishments in California
Museums in Shasta County, California
History museums in California

Fort Crook (California)


Day G. Turner (September 2, 1921 – February 8, 1945) was a United States Army soldier and a recipient of the United States military's highest decoration—the Medal of Honor—for his actions in World War II.

Career
Turner joined the Army from Nescopeck, Pennsylvania in September 1943, and by January 8, 1945, was serving as a Sergeant in Company B, 319th Infantry Regiment, 80th Infantry Division. On that day, in Dahl, Luxembourg, Turner led his squad in the defense of a house against an intense German attack. Fighting hand-to-hand at times, the squad successfully repulsed the Germans and took dozens of prisoners. Turner was later promoted to Staff Sergeant, but was killed in combat exactly one month after his actions in Dahl. He was posthumously awarded the Medal of Honor on June 28, 1945, and buried at the Luxembourg American Cemetery and Memorial.

Medal of Honor citation
Sergeant Turner's official Medal of Honor citation reads:
He commanded a 9-man squad with the mission of holding a critical flank position. When overwhelming numbers of the enemy attacked under cover of withering artillery, mortar, and rocket fire, he withdrew his squad into a nearby house, determined to defend it to the last man. The enemy attacked again and again and were repulsed with heavy losses. Supported by direct tank fire, they finally gained entrance, but the intrepid sergeant refused to surrender although 5 of his men were wounded and 1 was killed. He boldly flung a can of flaming oil at the first wave of attackers, dispersing them, and fought doggedly from room to room, closing with the enemy in fierce hand-to-hand encounters. He hurled handgrenade for handgrenade, bayoneted 2 fanatical Germans who rushed a doorway he was defending and fought on with the enemy's weapons when his own ammunition was expended. The savage fight raged for 4 hours, and finally, when only 3 men of the defending squad were left unwounded, the enemy surrendered. Twenty-five prisoners were taken, 11 enemy dead and a great number of wounded were counted. Sgt. Turner's valiant stand will live on as a constant inspiration to his comrades. His heroic, inspiring leadership, his determination and courageous devotion to duty exemplify the highest tradition of the military service.

Day G. Turner Memorial in Dahl

See also

List of Medal of Honor recipients
List of Medal of Honor recipients for World War II

Notes

References

1945 deaths
United States Army personnel killed in World War II
United States Army Medal of Honor recipients
People from Berwick, Pennsylvania
1921 births
World War II recipients of the Medal of Honor
United States Army non-commissioned officers
United States Army Infantry Branch personnel
Military personnel from Pennsylvania

Day G. Turner


Segerseni was an ancient Egyptian or Nubian chieftain of Nubia, likely reigning concurrently with the end of the 11th and beginning of the 12th Dynasty during the early Middle Kingdom.

Attestation
Segerseni is attested by one or two rock inscriptions discovered in Umbarakab (Khor-Dehmit) in Lower Nubia. Segerseni's throne name as given on the inscriptions remains in doubt as it was roughly carved and became badly weathered over time. It could be Menkhkare or Wadjkare. The former is now regarded as more probable. One of Segerseni's inscriptions possibly records a war in the unidentified region of Persenbet.

Segerseni is not attested on any of the Egyptian king lists.

Biography
Even though Segerseni adopted the titles of an Egyptian pharaoh, there is no evidence of him outside of Nubia. He was thus most likely a pretender to the Egyptian or Nubian throne headquartered in Lower Nubia, during a politically troubled period: either at the beginning of the First Intermediate Period, during the Second Intermediate Period, or in the time span including the reign of Mentuhotep IV of the 11th Dynasty and the early reign of Amenemhat I of the 12th Dynasty. The latter possibility is seen as more probable by Egyptologists. In particular, these two rulers seem to have had problems in being universally recognized as legitimate pharaohs.

It is known that Amenemhat I dispatched Khnumhotep I, the faithful Great Chief of the Oryx nome (the 16th nome of Upper Egypt) at Elephantine to Nubia in order to wipe out the last resistance against him there, but it is not known with certainty who was the leader of this resistance. It remains conjectural to posit that it was Segerseni. Furthermore, two other rulers based in Nubia, Iyibkhentre and Qakare Ini are known, likely from the same time period. They were both likely pretenders to the Egyptian throne, and the relationships between them and Segerseni are unknown. If Segerseni was indeed Amenemhat I's foe, he could have been fighting on Mentuhotep IV's side or for his own Nubian realm. Indeed, Nubia had gained its independence during the First Intermediate Period, as indicated by the military campaigns of Mentuhotep II in the region, only 40 years prior to Segerseni's conjectured lifetime.

References

Further reading
Henri Gauthier, "Nouvelles remarques sur la XIe dynastie", BIFAO 9 (1911), pp. 99–136.
Thomas Schneider, Lexikon der Pharaonen. Albatros, Düsseldorf 2002, , p. 259.

20th-century BC Pharaohs
People of the Eleventh Dynasty of Egypt
People of the Twelfth Dynasty of Egypt
Non-dynastic pharaohs
Nubian people

Segerseni


East Hancock is an unorganized territory in Hancock County, Maine, United States. The population was 85 at the 2020 census.

Geography
According to the United States Census Bureau, the unorganized territory has a total area of 481.2 square miles (1,246.4 km2), of which 444.3 square miles (1,150.6 km2) is land and 37.0 square miles (95.8 km2) (7.68%) is water.

The territory consists of thirteen townships located along the northern and eastern border of the county.

Demographics

As of the census of 2000, there were 73 people, 32 households, and 18 families residing in the unorganized territory. The population density was . There were 580 housing units at an average density of . The racial makeup of the unorganized territory was 97.26% White, 1.37% Native American, and 1.37% from two or more races.

There were 32 households, out of which 18.8% had children under the age of 18 living with them, 53.1% were married couples living together, 3.1% had a female householder with no husband present, and 43.8% were non-families. 34.4% of all households were made up of individuals, and 15.6% had someone living alone who was 65 years of age or older. The average household size was 2.28 and the average family size was 2.83.

In the unorganized territory the population was spread out, with 17.8% under the age of 18, 6.8% from 18 to 24, 20.5% from 25 to 44, 38.4% from 45 to 64, and 16.4% who were 65 years of age or older. The median age was 48 years. For every 100 females, there were 92.1 males. For every 100 females age 18 and over, there were 93.5 males.

The median income for a household in the unorganized territory was $31,875, and the median income for a family was $42,500. Males had a median income of $32,083 versus $12,083 for females. The per capita income for the unorganized territory was $18,156. There were no families and 2.8% of the population living below the poverty line, including no under eighteens and 13.3% of those over 64.

References

Unorganized territories in Maine
Populated places in Hancock County, Maine

East Hancock, Maine


Prior to its uniform adoption of proportional representation in 1999, the United Kingdom used first-past-the-post for the European elections in England, Scotland and Wales. The European Parliament constituencies used under that system were smaller than the later regional constituencies and only had one Member of the European Parliament each.

The constituency of London South East was one of them.

When it was created in England in 1979, it consisted of the Westminster Parliament constituencies of Beckenham, Bexleyheath, Chislehurst, Erith and Crayford, Orpington, Ravensbourne, Sidcup, Woolwich East and Woolwich West.

United Kingdom Parliamentary constituencies were redrawn in 1983 and the European constituencies were altered to reflect this. The new seat comprised the following Westminster constituencies: Beckenham, Bexleyheath, Chislehurst, Eltham, Erith and Crayford, Greenwich, Old Bexley and Sidcup, Orpington, Ravensbourne and Woolwich. These boundaries were used in 1984 and 1989. Greenwich was removed for the 1994 European Parliament election.

Members of the European Parliament

Elections

References

External links
 David Boothroyd's United Kingdom Election Results

South East
20th century in London
1979 establishments in England
1999 disestablishments in England
Constituencies established in 1979
Constituencies disestablished in 1999

London South East (European Parliament constituency)


Cuts Both Ways is the first solo album by Gloria Estefan. It was also Estefan's last album with the Miami Sound Machine. The album contains Latin music, dance and ballads.

This album was released in July 1989. Its first single was "Don't Wanna Lose You."

1989 albums
Pop albums
Gloria Estefan albums

Cuts Both Ways


Rhoon is a village that borders the municipality of the city of Rotterdam, South Holland, the Netherlands.

According to its history it was established in 1199 and was ruled by the lords of Duiveland. In the 14th century the village was struck by many floods.

In the last big flood, the North Sea flood of 1953, the Dutch government implemented the "deltawerken" (Delta Works). This is a large protection barrier of dikes and dams to keep the water of the North Sea out during high tides. In 1969 Rhoon also became part of this plan and a large dike was established around the island of IJsselmonde.

Rhoon is part of the island of IJsselmonde and situated in the south of this island.
On the lands outside the dikes is a small yacht marina on the banks of the river Oude Maas, and also a "griend" which is a tidal forest. The river Oude Maas has a tidal difference of around 1.2 meter in a twice daily cycle.

Since 1 January 1985, the village has been part of the municipality of Albrandswaard together with Poortugaal.

The village has a connection to the city of Rotterdam by Rotterdam Metro line D, through Rhoon station.

In Rhoon is the Dutch Consulate General of Ireland.

References

External links

Albrandswaard
Populated places in South Holland
Former municipalities of South Holland

Rhoon


An urban legend is an often circulated story that is not necessarily based on truth, but merely conjecture and rumor. However, there may or may not be a grain of truth from which the story originated.

Urban legends and the Internet
The Internet has made it easier for urban legends to spread, as people often spread them to their friends or family using e-mail. As a result, some websites such as Snopes.com and TruthOrFiction.com, among others, have been made that look at urban legends and try to see whether or not they are true.

An example of an urban legend is a report that years after the defeat of St Clair in 1791 at Ft Recovery Mercer Country Ohio - a skeleton of a Captain Roger Vanderberg was found in Miami County Ohio inside a tree along with a diary; in fact no one of this name was a casualty of the 1791 battle - it was a story that orginated in 1864 from a Scottish novel! Another example of a urban legend is a young woman and her mother going to visit the Paris Exposition; the mother falls ill, the daughter rushes off to get help only to find her mother gone! The woman either goes insane or is told the truth-her mother had the plague which was the reason for the coverup. This became the premise of a 1950s movie So Long at the Fair. In fact the basis for the legend was a story in 1897 in a Philadelphia newspaper...and no other sources in fact!

Other urban legends concern the Chase Burial Vault in Barbadoes although the lone account has no other basis in fact. Another urban legend concerns organized crime: In New York city at the turn of the century there was a "Murder Stable" where criminals killed one another. In fact, the report was exaggerated. Allegedly, an unknown killer named "Shotgun Man" committed dozens of murders with a shotgun in Chicago, Illinois after the turn of the century between 1910 and 1911 - although a check of a database of Chicago murders from that time period shows only one shotgun killings between 1900 and 1920.

References

Folklore

Urban legend


Boso (; c. 841 – 11 January 887) was a Frankish nobleman of the Bosonid family who was related to the Carolingian dynasty and who rose to become King of Lower Burgundy and Provence.

Origin
Boso was the son of Bivin of Gorze, count of Lotharingia, by Richildis, the daughter of Boso the Elder by his wife Engeltrude. His maternal aunt Teutberga was the wife of King Lothair II of Lotharingia. Boso was also the nephew of Count Boso of Valois, for whom he was named, and of Hucbert, lay abbot of St. Maurice's Abbey, to which Boso succeeded in 869.

Countship
In 870, King Charles the Bald of West Francia married Boso's sister Richilde. This marriage paved the way for Boso's career in the service of his royal brother-in-law. In the same year, Boso was appointed count of Lyon and Vienne, replacing Gerard of Roussillon. In 872, Charles appointed him chamberlain and magister ostiariorum (master of porters) to his heir Louis the Stammerer. Boso likewise received investiture as count of Bourges. Louis was reigning as a subordinate king of Aquitaine, but because of his youth, it was Boso who looked after the administration of that realm.

In the autumn of 875, Boso accompanied Charles on his first Italian campaign and at the diet of Pavia in February 876 he was appointed arch-minister and missus dominicus for Italy and elevated to the rank of duke. He became governor and count of Provence in 877. He acted as a viceroy and married Ermengarde, the only daughter of Emperor Louis II. Boso disapproved of Charles' second Italian campaign in 877 and conspired with other like-minded nobles against his king. After Charles's death in October, these nobles forced Charles's son to confirm their rights and privileges.

Boso also formed close relations to the papacy and accompanied Pope John VIII in September 878 to Troyes, where the Pope asked King Louis for his support in Italy. The Pope adopted Boso as his son and probably offered to crown Louis emperor. It is said that he wanted to crown Boso emperor.

Kingship

In April 879, Louis the Stammerer died, leaving two adult sons, Louis III and Carloman II. Boso joined with other western Frankish nobles and advocated making Louis III the sole heir of the western kingdom, but eventually both brothers were elected kings. Boso renounced allegiance to the brothers and in July claimed independence by claiming the title Dei gratia id quod sum: by the Grace of God, that is what I am. He also claimed that his imperial father-in-law had named him as his heir. On 15 October 879, the bishops and nobles of the region around the Rhône and Saône rivers assembled in the Synod of Mantaille.  They elected Boso king and successor to Louis the Stammerer, the first non-Carolingian king in Western Europe in more than a century. This event was the first "free election" among the Franks, without regard to royal descent, inspired by a canonical principle (but not constant practice) of ecclesiastical elections.

Boso's realm, usually called the Kingdom of Provence, comprised the ecclesiastical provinces of the archbishops of Arles, Aix, Vienne, Lyon (without Langres), and probably Besançon, and the dioceses of Tarentaise, Uzès, and Viviers.

After Louis and Carloman divided their father's realm at Amiens in March 880, the two brothers joined to march against Boso. They took Mâcon and the northern parts of Boso's realm. Then uniting their forces with those of Charles the Fat, they unsuccessfully besieged Vienne from August to November.

In August 882, Boso was again besieged at Vienne by his brother, Richard the Justiciar, duke of Burgundy and count of Autun, who took the city in September. Boso never regained much of his realm and was restricted to the county of Vienne.

He died in 887 and was succeeded by his son Louis the Blind.

Marriages
Boso was married twice. The identity of his first wife is not known; his second wife was Ermengard of Italy, whom he wed in March 876. Their issue was:
Guilla of Provence (December 873 – before 15 June 929), married firstly Rudolph I of Burgundy, secondly Hugh of Italy; her mother is reported to have been Ermengard, but this seems to be erroneous because she was born before Boso and Ermengarde's wedding
 Engelberge/Ethelberga, married William I, Duke of Aquitaine; her mother is reported to have been Ermengard
 Louis the Blind (before 884 – 5 June 928), possibly had a non-marital relationship, next supposedly married Anna/Eudocia Mamikonian (according to a letter that Christian Settipani attributes to Nicholas Mystikos), lastly married Adelaide of Burgundy, who might have been a daughter of his sister Guilla; his mother is reported to have been Ermengard

Notes

References

Sources

Further reading
MacLean, Simon. "The Carolingian Response to the Revolt of Boso, 879–887." Early Medieval Europe 10.1 (2001): 21–48.

840s births
887 deaths
Year of birth uncertain
9th-century monarchs in Europe
Frankish warriors
Bosonids
Kings of Lower Burgundy
Monarchs of the Carolingian Empire

Boso of Provence


Epistemological rupture (or epistemological break) is a notion introduced in 1938 by French philosopher Gaston Bachelard, and later used by Louis Althusser.

Bachelard proposed that the history of science is replete with "epistemological obstacles"—or unthought/unconscious structures that were immanent within the realm of the sciences, such as principles of division (e.g., mind/body). The history of science, Bachelard asserted, consisted in the formation and establishment of these epistemological obstacles, and then the subsequent tearing down of the obstacles. This latter stage is an epistemological rupture—where an unconscious obstacle to scientific thought is thoroughly ruptured or broken away from.

Etymology
Epistemology, from the Greek words episteme (knowledge) and logos ("word, speech") is the branch of philosophy that deals with the nature, origin and scope of knowledge. Rupture, from Old French rupture or Latin ruptura, is defined as an instance of breaking or bursting suddenly and completely, as well as a breach of a harmonious link in a figurative way.

See also

Notes and references

Concepts in the philosophy of science
Epistemology of science
Post-structuralism

Epistemological rupture


In astrodynamics, a hyperbolic trajectory (which is also an escape trajectory) refers to an object (such as an asteroid) which follows a path similar to a hyperbola around a central object. This motion follows Kepler's Laws. A hyperbolic trajectory occurs when the eccentricity of its orbit is greater than 1.

Other types of motion in astronomy include circular orbit, elliptical orbit, and parabolic trajectory.

Orbits

Hyperbolic trajectory


Baobab is the common name of a genus of trees (Adansonia). There are a total of eight types of its kind: six species live in the drier parts of Madagascar, two in mainland Africa, one in Australia and three in India. It is the national tree of Madagascar.

Other names
Other common names include 'boab', 'boaboa', 'bottle tree', 'the tree of life', 'upside-down tree', and 'monkey bread tree'. The trees reach heights of 5 to 30 meters (16 to 98 ft) and trunk diameters of 7 to 11 meters (23 to 36 ft.). Its trunk can hold up to 120,000 liters of water. For most of the year, the tree is leafless, and looks very much like it has its roots sticking up in the air.

Medicinal uses
Baobabs are one of the largest and most important trees in all of where they grow, as they are able to provide shelter and wood. The leaves of the tree are used for making soup and the tree has some medicinal purposes in some regions of Africa for treating ailments such as wounds, diarrhea, asthma, fever, and malaria.

Long life of baobab tree
The trees are long-lived, but just how long is disputed. The owners of Sunland Farm in Limpopo, South Africa have built a pub called "The Big Baobab Pub" inside the hollow trunk of the  high tree.  The tree is 47 m (155 ft) in circumference, and is said to have been carbon dated at over 6,000 years old.

Other uses
The baobab tree is known as the tree of life, with good reason. It can provide shelter, clothing, food, and water for the animal and human inhabitants of the African savannah regions. The cork-like bark and huge stem are fire resistant and are used for making cloth and rope. The leaves are used as condiments and medicines. The fruit, called "monkey bread", is edible, and full of vitamin C. As of 2010 experts estimate the potential international market at a billion united states dollars a year.

The fruit has a velvety shell and is about the size of a coconut, weighing about . It has a somewhat acidic flavour, described as 'somewhere between grapefruit, pear, and vanilla'.

The tree can store hundreds of liters of water, which is an adaptation to the harsh drought conditions of its environment. The tree may be tapped in dry periods.

Mature trees are usually hollow, providing living space for many animals and humans. Trees are even used as bars, barns, wine and beer shops and more.

References

Malvaceae
Trees

Baobab


Dr. Pricilla Nanyang (Priscila Nyanyang or Priscilla Nyayang Joseph Kuch) is a South Sudanese politician. She has served as deputy minister for gender, child and social welfare as well as minister without portfolio.

Education
Nanyang earned a Bachelors of Medicine and Surgery in 1978 from University of Khartoum. She received her Masters of Community Medicine from  in 1987 also from the University of Khartoum.

Career
Between 2005 and 2010 she served as a Sudan People's Liberation Movement (SPLM) member of National Assembly and Chairperson of the Human Rights Committee in the National Parliament. In 2007, Nanyang participated in an SPLM task force to try and facilitate peace talks in Darfur. Nanyang was one of seven women appointed to the South Sudanese cabinet in June 2010. She was appointed  Minister Without Portfolio in the Cabinet of South Sudan on 10 July 2011. As Minister Without Portfolio, Nanyang led an eight-week research project, called "Comprehensive Evaluation of the Government of South Sudan", to study how the South Sudanese Government was performing since its formation in 2005.

She is also the former deputy minister for gender, child and social welfare. In 2014 she coordinated a meeting of women peace activists in Juba "to advance the cause of peace, healing and reconciliation." As deputy minister, she traveled to New York City in 2013 for the 57th Seession of the Commission on the Status of Women and while in New York met with the Program on Peace-building and Rights at Columbia University's Institute for the Study of Human Rights. As of 2015 Nanyang also held the title of chairperson of the South Sudan Women Peace Network.

See also
 Agnes Kwaje Lasuba
 SPLM
 SPLA
 Cabinet of South Sudan

External links
Website of Government of South Sudan

References

Year of birth missing (living people)
Living people
Government ministers of South Sudan
21st-century South Sudanese women politicians
21st-century South Sudanese politicians
Women government ministers of South Sudan

Pricilla Nanyang


Namulauulu Alama Ieremia (born 27 October 1970) is a New Zealand rugby union coach and former international player for Western Samoa and New Zealand.

Early life
Ieremia was born in Sinamoga, a suburb of Apia, Samoa. He was educated in Samoa at Addington Primary School in Christchurch, New Zealand and later at Samoa College. He returned to New Zealand in 1991 to study geography at Victoria University, where he began playing rugby.

Playing career
Ieremia played provincial rugby with Wellington between 1992 and 2000, which included a National Provincial Championship title in his final season with the club. He played Super Rugby with the Hurricanes from its inaugural season in 1996, with Alama having the distinction of scoring the first ever try in Super rugby, against Auckland Blues in Palmerston North - Auckland Blues went on to win the match 36–28. The Hurricanes finished 9th at the end of the season. Alama's best season came in 1997, when the Hurricanes made it to the Semi finals haven finished third at the end of the Regular season. However the Hurricanes went down to the ACT Brumbies 33–20 in Canberra. Ieremia was a regular selection for the Hurricanes, forming a reliable and formidable midfield partnership with Jason O'Halloran.

In 2001, Ieremia moved to Japan to play for Suntory Sungoliath, which included a season as captain, before returning to New Zealand in 2004 after retiring from playing rugby.

International career
Ieremia began playing international rugby in 1992 for the national side Western Samoa. He made his debut on 13 June at Apia Park against Tonga, with Western Samoa winning 22–17. He earned 5 caps for Western Samoa, his last coming against the All Blacks at Eden Park on 31 July 1993, New Zealand winning 35–13, with the match being the first official international between the two countries.

With the lack of eligibility regulations in rugby before the professional era, Ieremia haven proven himself at Super Rugby level, was selected for the All Blacks in 1994. Ieremia's promotion to the All Blacks was rapid, due to the shock 2–0 series loss to France in June 1994. He was subsequently introduced for the three tests against the Springboks, playing at second five eighth with Frank Bunce, another who had been blooded by Samoa at test level, outside him at centre.

Ieremia was named in the All Blacks squad for the 1995 Rugby World Cup, but played only the pool match against Japan, where he also scored his first ever international try. For most of 1995 and 1996 the All Blacks' preference was for Walter Little as Bunce's partner and it was only an injury to Little that gave Ieremia his first extensive run as a regular test selection in 1997. An injury sustained during the 1998 Super 12 ruled him out of All Black selection that year, but he returned in 1999, and for the first part of the international season, he was used mainly at centre but for the bulk of the 1999 Rugby World Cup later in the year he was back at second five.

In 2000 he was again an All Black first choice, mainly again as a centre. Ieremia, a cheerful, articulate personality, was a strong, incisive runner and at 1.87m and 100 kg an imposing and powerful defender. He also had well developed skills and a solid boot. At his best, and when free from injury, he was one of the most consistently successful midfielders New Zealand rugby has had.

When he left New Zealand rugby at the end of the 2000 season to take up an overseas contract, Ieremia had played 40 matches for the All Blacks, including 30 tests.

Ieremia also represented Western Samoa at the 1993 Rugby World Cup Sevens and New Zealand at the 1997 Rugby World Cup Sevens.

Honors

New Zealand
Rugby World Cup / Webb Ellis Cup
Runners-up: 1995
Bledisloe Cup
Winners: 1997
Tri Nations
Winners: 1996, 1997, 1999
Runners-up: 2000

Western Samoa
South Pacific Championship
Winners: 1992, 1993

Wellington
National Provincial Championship
Winners: 2000

Coaching career
After retiring from playing rugby in 2004, Ieremia took up a coaching role with Suntory Sungoliath, specializing as backs and attack coach. After two seasons in Japan, which saw Suntory make it to the final for the first time in over five years, Ieremia returned to New Zealand in 2007 as an assistant coach with the Wellington Lions. He helped guide Wellington to their second consecutive final, only to lose to Auckland 23–14. He was later named as the WRFU Academy head coach, a position he held for a year.

On 25 September 2008, Alama Ieremia was appointed to the Hurricanes coaching team for the 2009 and 2010 Super 14 season. Ieremia earned the accolade of becoming the first former player to become part of the coaching staff of the team. In his first season as attack coach, he helped the Hurricanes to third in the regular season, before losing to the Chiefs in the semi-final 14–10. Despite this, the Hurricanes had scored more points than any other team of 380, their nearest rivals being the Blues with 339. The following year, saw the Hurricanes drop to eighth on the table, failing to make the play-off for the first time since 2007. When Colin Cooper left the side in 2010, Mark Hammett retained Ieremia as the attack coach for the 2011 and 2012 Super Rugby season. In 2012, he was praised in the media for bring through young All Blacks talent, and therefore was retained for a further 2 seasons. When Hammett left the club in 2014, Ieremia went with him, joining the Samoan national team as attack coach. His first game was a 33–14 loss to Japan. In February 2015, he was appointed interim general manager of Samoan rugby's high performance unit.

Head coach of Samoa
On 23 December 2015, he was named head coach of the Manu Samoa, taking over from Stephen Betham, who resigned after the 2015 Rugby World Cup.

In his first match in charge, he led Samoa to a 19–all draw against Georgia, in which saw 9 players making their debut. A week later they went down to Fiji 26–16, before finishing their June internationals with a 30–10 victory over Tonga seeing Samoa finish second in the 2016 World Rugby Pacific Nations Cup. During the 2016 end-of-year internationals, Ieremia led Samoa to a single victory, beating Canada 25–23. The other tests saw Samoa lose to France 52–8 and Georgia 20–16.

In the 2017 mid-year internationals, Samoa lost all four games. This included a 78–0 loss to New Zealand, which was the first time since 1996 that Samoa had failed to score any points in a test match. The following week saw Wales defeat Manu Samoa in Apia for the first time since 1986, losing 19–17. The 2017 World Rugby Pacific Nations Cup saw Samoa finish in last place for the first ever time, this came following a first loss to Samoa since 2011, 30–26, and a historic win for Fiji in Apia 38–16. It was the first time since 2002 that Fiji had won in Samoa, and set a new winning margin in Samoa of 22 points.

Following a review following Samoa's June/July campaign, Ieremia resigned as Samoan head coach on 5 August. He left the post with a 20% win rate, just 2 wins from 10 matches.

Auckland coach
In December 2017 he was appointed head coach for the Auckland Rugby Union.

Honors
Samoa (as assistant coach)
IRB Pacific Nations Cup
Winners: 2014 (joint with Japan)
Runners-up: 2015

Wellington (as assistant coach)
National Provincial Championship
Runners-up: 2007

References

External links
 All Blacks
 Hurricanes
 ESPN Scrum
 Samoa bio

1970 births
New Zealand international rugby union players
New Zealand rugby union players
New Zealand rugby union coaches
Rugby union centres
Rugby union players from Apia
Samoa international rugby union players
Samoan emigrants to New Zealand
Hurricanes (rugby union) players
Wellington rugby union players
New Zealand expatriate rugby union players
Expatriate rugby union players in Japan
New Zealand expatriate sportspeople in Japan
Tokyo Sungoliath players
Samoa international rugby sevens players
Male rugby sevens players
Samoan rugby union coaches
Living people
Samoan expatriate sportspeople in Japan
Samoan expatriate rugby union players
Samoan rugby union players
Samoa national rugby union team coaches
1995 Rugby World Cup players
1999 Rugby World Cup players

Alama Ieremia


Patricia Flatley Brennan is the director of the National Library of Medicine. Prior to that, she was the Lillian L. Moehlman Bascom Professor, School of Nursing and College of Engineering, at the University of Wisconsin–Madison. Brennan received a Master of Science in nursing from the University of Pennsylvania and a Ph.D. in industrial engineering from the University of Wisconsin–Madison. She served as chair of University of Wisconsin–Madison College of Engineering's Department of Industrial Engineering from 2007 to 2010.

Career
Following seven years of clinical practice in critical care nursing and psychiatric nursing, Brennan held several academic positions. She developed ComputerLink, an electronic network designed to reduce isolation and improve self-care among home care patients.

Brennan is the National Program Director of Project HealthDesign, a Robert Wood Johnson Foundation-funded initiative designed to stimulate the next generation of personal health records. In the context of that project, she coined the phrase "Observations of Daily Living" with her team, referring to observations people make about their health in everyday life. Additionally, she leads the WI-TECNE project, a statewide nursing faculty development effort supported by HRSA that aims to improve the integration of informatics and telehealth into nursing curricula. As of June 2009, Brennan was a theme leader of the Living Environments Lab at the Wisconsin Institutes for Discovery, researching home health care technologies using virtual reality and simulation technology.

A fellow of both the American Academy of Nursing (1991) and the American College of Medical Informatics (1993), Brennan was elected a member of the Institute of Medicine in 2001. In 2016, she was appointed director of the National Library of Medicine, where her term started in August 2016.

References

Living people
American nurses
American women nurses
Health informaticians
University of Wisconsin–Madison faculty
Fellows of the American Academy of Nursing
Nursing informatics
Nursing educators
Nursing researchers
Members of the National Academy of Medicine
University of Wisconsin–Madison College of Engineering alumni
Year of birth missing (living people)
National Institutes of Health people
21st-century American women scientists
United States National Library of Medicine
Place of birth missing (living people)
University of Pennsylvania School of Nursing alumni
American women academics

Patricia Flatley Brennan


Jubaland is the southern-most state in Somalia. It lies between Koofur Orsi and the Somali Sea. Before 1925, Jubaland was called British Jubaland. At that time, British Jubaland was controlled by the British empire. Afterwards it was given away to Italy for 15 years. In the 21st century Jubaland was again created. The men who created Jubaland were Barre Adan Hiraale, Cabdicasiis Aganje Garamgaram, Abdulahi Faratag, Mohamed Gandhi and Maxamed Boodhe. A person from Jubaland is called a Jubalander. Some Jubalander politicians was to secede (separate) from Somalia. Puntland and Jubaland have been described as Darod states. The 21st century federal states are modeled after the colonial era regions. For example Jubaland after Trans-juba, Koofur-orsi after Geledi, Hirshabelle after Benadir Company, Galmudug after Hobyo state, Puntland after Majeerteenia, and Khatumo or Maakhir, i.e. SSC State after Darawiish.

Related pages
Puntland

References

States of Somalia

Jubaland


Ernst, Prince of Saxe-Meiningen (Ernst, Prinz von Sachsen-Meiningen; 27 September 1859 – 29 December 1941) was the head of the house of Saxe-Meiningen from 1928 until his death.

Biography
He was born in Meiningen, the eldest son of the heir apparent to the duchy of Saxe-Meiningen, Prince Georg and his second wife, HSH Princess Feodora of Hohenlohe-Langenburg. His father succeeded to the throne in 1866. Ernst pursued a career in the army and retired as colonel in the Prussian cavalry. He received an honorary doctorate in philosophy from the University of Jena.

Ernst was married, morganatically, in Munich on 20 September 1892, to Katharina Jensen, daughter of the  painter Marie and the poet Wilhelm Jensen. Not permitted to share her husband's dynastic title, his wife was created Baroness von Saalfeld on their wedding day by Ernst's father, Georg II. Despite his unequal marriage, Ernst retained his succession rights to the duchy of Saxe-Meiningen.

When his older half-brother, the last reigning duke of Saxe-Meiningen, Bernhard III, died on 16 January 1928, Ernst succeeded him as head of the ducal house, but never reigned, since the monarchy was abolished at the end of World War I in 1918. Rather than his own son, Ernst's nephew Georg, Prince of Saxe-Meiningen, succeeded him as head of the house following his death at Schloss Altenstein.

Children
Ernst and Katharina had six children:

Baron Georg Wilhelm von Saalfeld (11 June 1893-29 April 1916) killed in action at the age of twenty-two.
Baroness Elisabeth Helen Adelheid Marie von Saalfeld (2 February 1895-4 June 1934) she married Dr. Johann Duken on 25 April 1917.
Baron Ernst Friedrich Heinrich Paul von Saalfeld (4 July 1896-28 May 1915) killed in action at the age of eighteen.
Baron Ralf Erich von Saalfeld (28 March 1900-22 July 1947) he married Marie Seitz (1903-1931) on 11 October 1925. They had two children. He remarried Melanie von Bismarck on 16 August 1936. They had four children.
Baron Sven Hans Heinrich Bernhard von Saalfeld (18 September 1903-13 December 1998) he married Elisabeth Faust on 20 March 1936 and they were divorced on 6 November 1952. They had five children.
Baron Enzio Heinrich Waldemar Carl von Saalfeld (7 July 1908-31 March 1941) he married Rut Viererbe on 28 February 1936. They had four children.

Ancestry

References

External links
Saalfeld family

House of Saxe-Meiningen
1859 births
1941 deaths
People from Meiningen
Princes of Saxe-Meiningen
Sons of monarchs

Ernst, Prince of Saxe-Meiningen


Gertrude of Flanders (c. 1070–1117), was a Countess of Louvain and Landgravine of Brabant by marriage to Henry III, Count of Leuven, and a Duchess of Lorraine by marriage to Theodoric II, Duke of Lorraine. At the time the duchy was the upper Lorraine, since 959 separated from the duchy of Lower Lorraine.

Life
Gertrude was daughter of Robert I, Count of Flanders and Gertrude of Saxony. Robert was son of Baldwin V of Flanders and Adèle, a daughter of King Robert II of France, and Gertrude daughter of the Duke of Saxony.  She was sister of Robert II, Count of Flanders (c. 1065 – 1111), "Robert the Crusader".

Leuven and Brabant
Gertrude married firstly Henry III, Count of Leuven (died wounded in a tournament in Tournai in 1095), of the House of Reginar. He was count of Louvain from 1078 to 1095 and landgrave of Brabant from 1085. At Henry's death, his brother Godfrey I succeeded as count and landgrave. From 1106 he also became duke of Lower Lorraine.

They had four children, probably all daughters (born about 1092-1096), assumingly including:
Adelaide (d. 1158), wife of duke Simon I of Lorraine (1076 – 1138), son of her stepfather Theodoric with Hedwige (d. c. 1090).
Gertrude, wife to Lambert, count of Montaigu and Clermont.

Lorraine
Secondly in 1096 she married Theodoric II, Duke of Lorraine "Thierry" (d. 1115), son of Gérard of Alsace, Count of Metz, Duke of Lorraine (-1070), of the House of Lorraine-Alsace. Thierry was a widower with a son Simon, and a daughter Gertrude.
They had the following issue:
 Thierry of Alsace "Theodoric" (c. 1099 – 1168), lord of Bitche, also Count of Flanders from 1128. Married to Sibylla of Anjou, and father to Margaret I, Countess of Flanders and Matthew, Count of Boulogne
Henry I (d. 1165), bishop of Toul
Ida, married Sigefroy (d. 1104), count of Burghausen
Ermengarde, married Bernard III Gros de Brancion (fr)
Gisela, married Frederick, count of Saarbrücken.

Ancestry

See also
Dukes of Lorraine family tree

References

Sources

House of Flanders
House of Reginar
House of Metz
House of Billung
1070s births
1117 deaths
Year of birth uncertain
11th-century French nobility
11th-century French women
11th-century German nobility
11th-century German women
12th-century German nobility
12th-century German women

Gertrude of Flanders, Duchess of Lorraine


Manda Ophuis (born 27 November 1980) is a Dutch former singer who is best known for being the lead vocalist in the symphonic rock band Nemesea. She has been involved in music since a young age.

Biography
In 1998, Ophuis started taking singing lessons. Her teacher was a student at the conservatory in Groningen, where she herself was admitted a year later. There she began taking vocal lessons with Floor van Zutphen who remained her vocal teacher during her time at the conservatory (2000–2004).

In 2003, Ophuis started taking classical singing lessons as well, also with a student from the conservatory. She took those lessons for two years. She graduated in 2004. In 2005, Ophuis found a new vocal teacher in Kees Taal. Taal taught her about breathing, resonance and how to use the whole body as an instrument.

In 2011, Ophuis decided that she wanted to broaden her range and started taking singing lessons with Setske Mostaert as well.

In August 2016, Ophuis quit the band after 14 years. She has continued in music, working with children.

Influences
Ophuis's main inspirations are Anneke van Giersbergen, Tori Amos, Christina Aguilera, and Kelly Clarkson.

References

External links

1980 births
Living people
Dutch rock singers
21st-century Dutch singers

Manda Ophuis


Paradiso (; Italia untuk "Firdaus" atau "Surga") adalah bagian ketiga dan terakhir dari Divine Comedy karya Dante, menyusul Inferno dan Purgatorio. Karya tersebut adalah sebuah pengisahan alegori dari perjalanan Dante ke Surga, dipandu oleh Beatrice, yang melambangkan teologi.

Pranala luar

 World of Dante Multimedia website that offers Italian text of Divine Comedy, Allen Mandelbaum's translation, gallery, interactive maps, timeline, musical recordings, and searchable database for students and teachers by Deborah Parker and IATH (Institute for Advanced Technologies in the Humanities) of the University of Virginia
 Princeton Dante Project  Website that offers the complete text of the Divine Comedy (and Dante's other works) in Italian and English along with audio accompaniment in both languages. Includes historical and interpretive annotation.
 Dante Dartmouth Project: Full text of more than 70 Italian, Latin, and English commentaries on the Commedia, ranging in date from 1322 (Iacopo Alighieri) to the 2000s (Robert Hollander)
 Dante's Divine Comedy presented by the Electronic Literature Foundation. Multiple editions, with Italian and English facing page and interpolated versions.
 The Comedy in English: trans. Cary (with Doré's illustrations) (zipped HTML downloadable from Project Gutenberg), Cary/Longfellow/Mandelbaum parallel edition
 On-line Concordance to the Divine Comedy
 Audiobooks: Public domain recordings from LibriVox (in Italian, Longfellow translation); some additional recordings
 Danteworlds, multimedia presentation of the Divine Comedy for students by Guy Raffa of the University of Texas
 Dante's Places: a map (still a prototype) of the places named by Dante in the Commedia, created with GoogleMaps. An explanatory PDF is available for download at the same page
 Gustave Dore - Paradiso Complete 18 hi-res pics album

Virgil

Paradiso (Dante)


The Gujarat Sultanate, or the Sultanate of Guzerat, was a late medieval Indian kingdom established in the early 15th century in Western India, primarily in the present-day state of Gujarat, India. The kingdom was founded by Muzaffar Shah I who was appointed as Tughlaq governor of Gujarat after the death of his father in 1371. Following Timur's invasion of the Delhi Sultanate, Delhi was devastated and its rule weakened considerably, so he declared himself independent in 1394, and formally established the Sultanate. The next sultan, his grandson Ahmad Shah I moved the capital to Ahmedabad in 1411. His successor Muhammad Shah II subdued most Rajput chieftains. The prosperity of the sultanate reached its zenith during the rule of Mahmud Begada. He also subdued most Gujarati Rajput chieftains and built a navy off the coast of Diu. In 1509, the Portuguese empire wrested Diu from the Sultanate in the Battle of Diu (1509). The Mughal emperor Humayun attacked Gujarat in 1535 and briefly occupied it, during which Bombay, Bassein & Daman would become a Portuguese colony, thereafter Bahadur Shah was killed by the Portuguese while making a deal in 1537. The end of the sultanate came in 1573, when Akbar annexed Sultanate of Guzerat into his empire. The last ruler Muzaffar Shah III was taken a prisoner to Agra. In 1583, he escaped from the prison and with the help of the nobles succeeded to regain the throne for a short period before being defeated by Akbar's minister Abdul Rahim Khan-i-Khanan.

Origin
The Muzaffarid dynasty was founded by Zafar Khan. There are multiple theories behind the origin of the Muzaffarids. It is said that Zafar Khan's father Wajih-ul-Mulk (Saharan) and his brother were influential Chaudharis who were agriculturists by profession but could also muster thousands of fighting men on their call. According to Shaikh Sikandar Ibn Muhammad's Mirati Sikandari, who was a contemporary of Gujarat Sultans, Sadhāran/Sahāran had a long list of ancestors that eventually traced to Rāmacandra. This claim of the sultans' links with the solar lineage is not found very often in texts and inscriptions they patronised. He has been stated as a Punjabi Rajput or a Khatri with origins in south Punjab. Misra, on the basis of the Mirat-i-Sikandari, states that Tank were Khatris who were agrarian people belonging to south Punjab. According to Aparna Kapadia, Saharan, the father of Zafar Khan, was probably a Tank Rajput who lived in Thanesar in modern-day Haryana.  Other historians such as Dr. V.K Agnihotri and Saiyid Athar Abbas Rizvi even wrote that Sadhāran was a Jat convert to Islam. American historian Richard M. Eaton simply described Zafar Khan being the son of a "peasant convert to Islam". Bahadur Shah has been described as an Afghan king by some scholars during his reign as the kingdom became a stronghold for Afghan nobles.

History

Early rulers
Delhi Sultan Firuz Shah Tughluq appointed Malik Mufarrah, also known as Farhat-ul-Mulk and Rasti Khan governor of Gujarat in 1377. In 1387, Sikandar Khan was sent to replace him, but he was defeated and killed by Farhat-ul-Mulk. In 1391, Sultan Nasir-ud-Din Muhammad bin Tughluq appointed Zafar Khan, the son of Wajih-ul-Mulk as governor of Gujarat and conferred him the title of Muzaffar Khan (r. 1391 - 1403, 1404 - 1411). In 1392, he defeated Farhat-ul-Mulk in the battle of Kamboi, near Anhilwada Patan and occupied the city of Anhilwada Patan.

In 1403, Zafar Khan's son Tatar Khan urged his father to march on Delhi, which he declined. As a result, in 1408, Tatar imprisoned him in Ashawal (future Ahmedabad) and declared himself sultan under the title of Muhammad Shah I (r. 1403 - 1404). He marched towards Delhi, but on the way he was poisoned by his uncle, Shams Khan. After the death of Muhammad Shah, Muzaffar was released from the prison and he took over the control over administration. In 1407, he declared himself as Sultan Muzaffar Shah I, took the insignia of royalty and issued coins in his name. After his death in 1411, he was succeeded by his grandson, the son of Tatar Khan, Ahmad Shah I.

Ahmad Shah I
Soon after his accession, Ahmad Shah I was faced with a rebellion of his uncles. The rebellion was led by his eldest uncle Firuz Khan, who declared himself king. Ultimately Firuz and his brothers surrendered to him. During this rebellion Sultan Hushang Shah of Malwa Sultanate invaded Gujarat. He was repelled this time but he invaded again in 1417 along with Nasir Khan, the Farooqi dynasty ruler of Khandesh and occupied Sultanpur and Nandurbar. Gujarat army defeated them and later Ahmad Shah led four expeditions into Malwa in 1419, 1420, 1422 and 1438.

In 1429, Kanha Raja of Jhalawad with the help of the Bahmani Sultan Ahmad Shah ravaged Nandurbar. But Ahmad Shah's army defeated the Bahmani army and they fled to Daulatabad. The Bahmani Sultan Ahmad Shah sent strong reinforcements and the Khandesh army also joined them. They were again defeated by the Gujarat army. Finally, Ahmad Shah annexed Thana and Mahim from Bahmani Sultanate.

At the beginning of his reign, he founded the city of Ahmedabad which he styled as Shahr-i-Mu'azzam (the great city) on the banks of Sabarmati River. He shifted the capital from Anhilwada Patan to Ahmedabad. The Jami Masjid (1423) in Ahmedabad were built during his reign. Sultan Ahmad Shah died in 1443 and succeeded by his eldest son Muhammad Shah II.

Successors of Ahmad Shah I
Muhammad Shah II (r. 1442 - 1451) first led a campaign against Idar and forced its ruler, Raja Hari Rai or Bir Rai to submit to his authority. He then exacted tribute from the Rawal of Dungarpur. In 1449, he marched against Champaner, but the ruler of Champaner, Raja Kanak Das, with the help of Malwa Sultan Mahmud Khilji forced him to retreat. On the return journey, he fell seriously ill and died in February 1451. After his death, he was succeeded by his son Qutb-ud-Din Ahmad Shah II (r. 1451 - 1458). Ahmad Shah II defeated Khilji at Kapadvanj. He helped Firuz Khan ruling from Nagaur against Rana Kumbha of Chittor's attempt to overthrow him. After death of Ahmad Shah II in 1458, the nobles raised his uncle Daud Khan, son of Ahmad Shah I, to the throne.

Mahmud Begada

But within a short period of seven or twenty-seven days, the nobles deposed Daud Khan and set on the throne Fath Khan, son of Muhammad Shah II. Fath Khan, on his accession, adopted the title Abu-al Fath Mahmud Shah, popularly known as Mahmud Begada. He expanded the kingdom in all directions. He received the sobriquet Begada, which literally means the conqueror of two forts, probably after conquering Girnar and Champaner forts. Mahmud died on 23 November 1511.

Muzaffar Shah II and his successors

Khalil Khan, son of Mahmud Begada succeeded his father with the title Muzaffar Shah II. In 1519, Rana Sanga of Chittor defeated a joint army of Malwa and Gujarat sultanates and took Mahmud Shah II of Malwa captive. Muzaffar Shah sent an army to Malwa but their service was not required as Rana Sanga had generously restored Mahmud Shah II to the throne.However,Rana Sanga defeated Ibrahim Lodhi of Delhi at Battle of Dholpur around the same time and Conquered Much of Malwa along with Chanderi and he bestowed it to his Vassal Medini Rai who ruled over Malwa under his lordship with Chanderi as his capital.The victory brought Rajputs within day's march of Agra and Delhi and made them contender of supremacy of Northern India. Rana Sanga later invaded Gujarat and plundered the Sultanate's treasuries, greatly damaging its prestige, Sanga also annexed northern Gujarat and appointed one of his Rajput vassals to rule there. The invasion of Rana weakened Gujarat, however after Rana Sanga's death, the sultans of Gujarat freed their kingdom from Rajputs and grew even more powerful as they sacked Chittor fort in 1535. He died on 5 April 1526 and was succeeded by his eldest son, Sikandar.

After few months, Sikandar Sháh was murdered by a noble Imád-ul-Mulk, who seated a younger brother of Sikandar, named Násir Khán, on the throne with the title of Mahmúd Shah II and governed on his behalf. Other son of Muzaffar Shah II, Bhadur Khan returned from outside of Gujarat and the nobles joined him. Bahádur marched at once on Chámpáner, captured and executed Imád-ul-Mulk and poisoning Násir Khán ascended the throne in 1527 with the title of Bahádur Sháh.

Bahadur Shah and his successors

Bahadur Shah expanded his kingdom and made expeditions to help neighbouring kingdoms. In 1532, Gujarat came under attack of the Mughal Emperor Humayun and fell. Bahadur Shah regained the kingdom in 1536 but he was killed by the Portuguese on board the ship when making a deal with them.

Bahadur had no son, hence there was some uncertainty regarding succession after his death. Muhammad Zaman Mirza, the fugitive Mughal prince made his claim on the ground that Bahadur's mother adopted him as her son. The nobles selected Bahadur's nephew Miran Muhammad Shah of Khandesh as his successor, but he died on his way to Gujarat. Finally, the nobles selected Mahmud Khan, the son of Bahadur's brother Latif Khan as his successor and he ascended to the throne as Mahmud Shah III in 1538. Mahmud Shah III had to battle with his nobles who were interested in independence. He was killed in 1554 by his servant. Ahmad Shah III succeeded him but now the reigns of the state were controlled by the nobles who divided the kingdom between themselves. He was assassinated in 1561. He was succeeded by Muzaffar Shah III.

Muzaffar Shah III
Mughal Emperor Akbar annexed Gujarat in his empire in 1573 and Gujarat became a Mughal Subah (province). Muzaffar Shah III was taken prisoner to Agra. In 1583, he escaped from the prison and with the help of the nobles succeeded to regain the throne for a short period before being defeated by Akbar's general Abdul Rahim Khan-I-Khana in January 1584. He fled and finally took asylum under Jam Sataji of Nawanagar State. The Battle of Bhuchar Mori was fought between the Mughal forces led by Mirza Aziz Koka and the combined Kathiawar forces in 1591 to protect him. He finally committed suicide when he was surrendered to the Mughal.

List of rulers

Administration

Gujarát was divided politically into two main parts; one, called the khálsah or crown domain administered directly by the central authority; the other, on payment of tribute in service or in money, left under the control of its former rulers. The amount of tribute paid by the different chiefs depended, not on the value of their territory, but on the terms granted to them when they agreed to become feudatories of the king. This tribute was occasionally collected by military expeditions headed by the king in person and called mulkgíri or country-seizing circuits.

The internal management of the feudatory states was unaffected by their payment of tribute. Justice was administered and the revenue collected in the same way as under the Chaulukya kings. The revenue consisted, as before, of a share of the crops received in kind, supplemented by the levy of special cesses, trade, and transit dues. The chief's share of the crops differed according to the locality; it rarely exceeded one-third of the produce, it rarely fell short of one-sixth. From some parts the chief's share was realised directly from the cultivator by agents called ; from other parts the collection was through superior landowners.

Districts and crown lands
The Áhmedábád kings divided the portion of their territory which was under their direct authority into districts or sarkárs. These districts were administered in one of two ways. They were either assigned to nobles in support of a contingent of troops, or they were set apart as crown domains and managed by paid officers. The officers placed in charge of districts set apart as crown domains were called muktiă. Their chief duties were to preserve the peace and to collect the revenue. For the maintenance of order, a body of soldiers from the army headquarters at Áhmedábád was detached for service in each of these divisions, and placed under the command of the district governor. At the same time, in addition to the presence of this detachment of regular troops, every district contained certain fortified outposts called thánás, varying in number according to the character of the country and the temper of the people. These posts were in charge of officers called thánadárs subordinate to the district governor. They were garrisoned by bodies of local soldiery, for whose maintenance, in addition to money payments, a small assignment of land was set apart in the neighbourhood of the post. On the arrival of the tribute-collecting army the governors of the districts through which it passed were expected to join the main body with their local contingents. At other times the district governors had little control over the feudatory chiefs in the neighbourhood of their charge. The Gujarat Sultanate had comprised twenty-five sarkars (administrative units).

Fiscal

For fiscal purposes each district or sarkár was distributed among a certain number of sub-divisions or parganáhs, each under a paid official styled ámil or tahsildár. These sub-divisional officers realised the state demand, nominally one-half of the produce, by the help of the headmen of the villages under their charge. In the sharehold and simple villages of North Gujarát these village headmen were styled Patel or according to Muslim writers mukaddams and in the simple villages of the south they were known as Desai. They arranged for the final distribution of the total demand in joint villages among the shareholders, and in simple villages from the individual cultivators. The sub-divisional officer presented a statement of the accounts of the villages in his sub-division to the district officer, whose record of the revenue of his whole district was in turn forwarded to the head revenue officer at court. As a check on the internal management of his charge, and especially to help him in the work of collecting the revenue, with each district governor was associated an accountant. Further that each of these officers might be the greater check on the other, Ahmad Shah I enforced the rule that when the governor was chosen from among the royal slaves the accountant should be a free man, and that when the accountant was a slave the district governor should be chosen from some other class. This practise was maintained till the end of the reign of Muzaffar Sháh II, when, according to the Mirăt-i-Áhmedi, the army became much increased, and the ministers, condensing the details of revenue, farmed it on contract, so that many parts formerly yielding one rupee now produced ten, and many others seven eight or nine, and in no place was there a less increase than from ten to twenty per cent. Many other changes occurred at the same time, and the spirit of innovation creeping into the administration the wholesome system of checking the accounts was given up and mutiny and confusion spread over Gujarát.

Sources of history
Mirat-i-Sikandari is a Persian work on the complete history of Gujarat Sultanate written by Sikandar, son of Muhammad aka Manjhu, son of Akbar who wrote it soon after Akbar conquered Gujarat. He had consulted earlier works of history and the people of authority. Other Persian works of the history of Gujarat Sultanate are Tarikh-i-Muzaffar Shahi about reign of Muzaffar Shah I, Tarik-i-Ahmad Shah in verse by Hulvi Shirazi, Tarikh-i-Mahmud Shahi, Tabaqat-i-Mahmud Shahi, Maathi-i-Mahmud Shahi about Mahmud I, Tarikh-i-Muzaffar Shahi about Muzaffar Shah II's conquest of Mandu, Tarikh-i-Bahadur Shahi aka Tabaqat-i-Husam Khani, Tarikh-i-Gujarat by Abu Turab Vali, Mirat-i-Ahmadi. Other important work in Arabic about history of Gujarat includes Zafarul-Walih bi Muzaffar wa Alih by Hajji Dabir.

Architecture

The distinctive Indo-Islamic architecture style of Gujarat drew micro-architectural elements from earlier Maru-Gurjara architecture and employed them in mihrab, roofs, doors, minarets and facades. In the 15th century, the Indo-Islamic style of Gujarat is especially notable for its inventive and elegant use of minarets. They are often in pairs flanking the main entrance, mostly rather thin and with elaborate carving at least at the lower levels. Some designs push out balconies at intervals up the shaft; the most extreme version of this was in the lost upper parts of the so-called "shaking minarets" at the Jama Mosque, Ahmedabad, which fell down in an earthquake in 1819. This carving draws on the traditional skills of local stone-carvers, previously exercised on Hindu temples in the Māru-Gurjara and other local styles.

Gujarat Sultans built lavishly, particularly in the capital, Ahmedabad. The sultanate commissioned mosques such as the Jami Masjid of Ahmedabad, Jama Masjid at Champaner, Qutbuddin Mosque, Rani Rupamati Mosque, Sarkhej Roza, Sidi Bashir Mosque, Kevada Mosque, Sidi Sayyed Mosque, Nagina Mosque and Pattharwali Masjid, as well as structures such as Teen Darwaza, Bhadra Fort and the Dada Harir Stepwell in Ahmedabad.

The Champaner-Pavagadh Archaeological Park, the 16th century capital of Gujarat Sultanate, documents the early Islamic and pre-Mughal city that has remained without any change.

Indo-Islamic architecture style of Gujarat presages many of the architectural elements later found in Mughal architecture, including ornate mihrabs and minarets, jali (perforated screens carved in stone), and chattris (pavilions topped with cupolas).

References

Bibliography

External links

Coins of the Gujarat Sultanate

History of Gujarat

Gujarat Sultanate


Stadia marks, also called stadia lines or stadia hairs, are crosshairs on the reticle of a theodolite or other surveying instrument that allow stadiametric rangefinding.

Etymology
The term stadia mark derives from the obsolete unit of distance, the stadion, derived from the Greek measurement of a stadium. Several different stadia were defined, such as the Greek stadion and Egyptian stadion.

Usage

A typical surveyor's instrument reticle has two pairs of stadia marks. One pair are on the horizontal centreline and the other on the vertical cross hair. Each functions in the same manner and are placed for measuring on either axis.

The stadia marks are set a specific length apart. This length is chosen so that there is a fixed, integer ratio between the difference of the  rod readings and the distance from the telescope to the rod. This ratio is known as the stadia constant or stadia interval factor. Thus the formula for distance is

where

For example, a typical stadia mark pair are set so that the ratio is 100. If one observes a vertical length on a stadia rod, rule or levelling rod with the telescope and sees that the rod spans 0.500 m between the marks (the stadia interval), then the horizontal distance from the instrument to the rod is:
 0.500m x 100 = 50 m.

In the adjacent image, the upper stadia mark is at 1.500 m and the lower at 1.345 m. The difference is 0.155 m. Thus the distance from the instrument to the levelling rod is:
 0.155 x 100 = 15.5 m.

See also
Stadiametric rangefinding
Tacheometry
Theodolite
Dumpy level
Plane table
Levelling rod

References

Sources
Raymond Davis, Francis Foote, Joe Kelly, Surveying, Theory and Practice, McGraw-Hill Book Company, 1966 LC 64-66263

Measuring instruments
Surveying

Stadia mark


Vaisakh (Punjabi: ਵੈਸਾਖ, Shahmukhi Punjabi: ویساکھ) is the second month in the Nanakshahi calendar. This month is usually in  April and May in the Gregorian calendar. It is the same as Vaisakha in the Hindu calendar and the Indian national calendar. Usually, it is when crops are harvested in the Punjab region.

Months

Vaisakh