The Smith chart (sometimes also called Smith diagram, Mizuhashi chart (), Mizuhashi–Smith chart (), Volpert–Smith chart () or Mizuhashi–Volpert–Smith chart), is a graphical calculator or nomogram designed for electrical and electronics engineers specializing in radio frequency (RF) engineering to assist in solving problems with transmission lines and matching circuits.

It was independently proposed by Tōsaku Mizuhashi () in 1937, and by  () and Phillip H. Smith in 1939.
Starting with a rectangular diagram, Smith had developed a special polar coordinate chart by 1936, which, with the input of his colleagues Enoch B. Ferrell and James W. McRae, who were familiar with conformal mappings, was reworked into the final form in early 1937, which was eventually published in January 1939.
While Smith had originally called it a "transmission line chart" and other authors first used names like "reflection chart", "circle diagram of impedance", "immittance chart" or "Z-plane chart", early adopters at MIT's Radiation Laboratory started to refer to it simply as "Smith chart" in the 1940s, a name generally accepted in the Western world by 1950.

The Smith chart can be used to simultaneously display multiple parameters including impedances, admittances, reflection coefficients,  scattering parameters, noise figure circles, constant gain contours and regions for unconditional stability, including mechanical vibrations analysis. The Smith chart is most frequently used at or within the unity radius region. However, the remainder is still mathematically relevant, being used, for example, in oscillator design and stability analysis.
While the use of paper Smith charts for solving the complex mathematics involved in matching problems has been largely replaced by software based methods, the Smith chart is still a very useful method of showing how RF parameters behave at one or more frequencies, an alternative to using tabular information.
Thus most RF circuit analysis software includes a Smith chart option for the display of results and all but the simplest impedance measuring instruments can plot measured results on a Smith chart display.

Overview

The Smith chart is a mathematical transformation of the two-dimensional Cartesian complex plane. Complex numbers with positive real parts map inside the circle. Those with negative real parts map outside the circle.
If we are dealing only with impedances with non-negative resistive components, our interest is focused on the area inside the circle.
The transformation, for an impedance Smith chart, is:

where  i.e., the complex impedance,  normalized by the reference impedance, . The impedance Smith chart is then an Argand plot of impedances thus transformed. Impedances with non-negative resistive components will appear inside a circle with unit radius; the origin will correspond to the reference impedance, .

The Smith chart is plotted on the complex reflection coefficient plane in two dimensions and may be scaled in normalised impedance (the most common), normalised admittance or both, using different colours to distinguish between them. These are often known as the Z, Y and YZ Smith charts respectively. Normalised scaling allows the Smith chart to be used for problems involving any characteristic or system impedance which is represented by the center point of the chart. The most commonly used normalization impedance is 50 ohms. Once an answer is obtained through the graphical constructions described below, it is straightforward to convert between normalised impedance (or normalised admittance) and the corresponding unnormalized value by multiplying by the characteristic impedance (admittance). Reflection coefficients can be read directly from the chart as they are unitless parameters.

The Smith chart has a scale around its circumference or periphery which is graduated in wavelengths and degrees. The wavelengths scale is used in distributed component problems and represents the distance measured along the transmission line connected between the generator or source and the load to the point under consideration. The degrees scale represents the angle of the voltage reflection coefficient at that point. The Smith chart may also be used for lumped-element matching and analysis problems.

Use of the Smith chart and the interpretation of the results obtained using it requires a good understanding of AC circuit theory and transmission-line theory, both of which are prerequisites for RF engineers.

As impedances and admittances change with frequency, problems using the Smith chart can only be solved manually using one frequency at a time, the result being represented by a point. This is often adequate for narrow band applications (typically up to about 5% to 10% bandwidth) but for wider bandwidths it is usually necessary to apply Smith chart techniques at more than one frequency across the operating frequency band. Provided the frequencies are sufficiently close, the resulting Smith chart points may be joined by straight lines to create a locus.

A locus of points on a Smith chart covering a range of frequencies can be used to visually represent:
how capacitive or how inductive a load is across the frequency range
how difficult matching is likely to be at various frequencies
how well matched a particular component is.
The accuracy of the Smith chart is reduced for problems involving a large locus of impedances or admittances, although the scaling can be magnified for individual areas to accommodate these.

Mathematical basis

Actual and normalised impedance and admittance
A transmission line with a characteristic impedance of  may be universally considered to have a characteristic admittance of  where

Any impedance,  expressed in ohms, may be normalised by dividing it by the characteristic impedance, so the normalised impedance using the lower case zT is given by

Similarly, for normalised admittance

The SI unit of impedance is the ohm with the symbol of the upper case Greek letter omega (Ω) and the SI unit for admittance is the siemens with the symbol of an upper case letter S. Normalised impedance and normalised admittance are dimensionless. Actual impedances and admittances must be normalised before using them on a Smith chart. Once the result is obtained it may be de-normalised to obtain the actual result.

The normalised impedance Smith chart

Using transmission-line theory, if a transmission line is terminated in an impedance () which differs from its characteristic impedance (), a standing wave will be formed on the line comprising the resultant of both the incident or forward () and the reflected or reversed () waves. Using complex exponential notation:
 and

where

 is the temporal part of the wave
 is the spatial part of the wave and
 where
 is the angular frequency in radians per second (rad/s)
 is the frequency in hertz (Hz)
 is the time in seconds (s)
 and  are constants
 is the distance measured along the transmission line from the load toward the generator in metres (m)
Also
 is the propagation constant which has SI units radians/meter
where
 is the attenuation constant in nepers per metre (Np/m)
 is the phase constant in radians per metre (rad/m)
The Smith chart is used with one frequency () at a time, and only for one moment () at a time, so the temporal part of the phase () is fixed. All terms are actually multiplied by this to obtain the instantaneous phase, but it is conventional and understood to omit it. Therefore,
 and

where  and  are respectively the forward and reverse voltage amplitudes at the load.

The variation of complex reflection coefficient with position along the line

The complex voltage reflection coefficient  is defined as the ratio of the reflected wave to the incident (or forward) wave. Therefore,

where  is also a constant.

For a uniform transmission line (in which  is constant), the complex reflection coefficient of a standing wave varies according to the position on the line. If the line is lossy ( is non-zero) this is represented on the Smith chart by a spiral path. In most Smith chart problems however, losses can be assumed negligible () and the task of solving them is greatly simplified. For the loss free case therefore, the expression for complex reflection coefficient becomes

where  is the reflection coefficient at the load, and  is the line length from the load to the location where the reflection coefficient is measured. The phase constant  may also be written as

where  is the wavelength within the transmission line at the test frequency.

Therefore,

This equation shows that, for a standing wave, the complex reflection coefficient and impedance repeats every half wavelength along the transmission line. The complex reflection coefficient is generally simply referred to as reflection coefficient. The outer circumferential scale of the Smith chart represents the distance from the generator to the load scaled in wavelengths and is therefore scaled from zero to 0.50.

The variation of normalised impedance with position along the line
If  and  are the voltage across and the current entering the termination at the end of the transmission line respectively, then

and
.
By dividing these equations and substituting for both the voltage reflection coefficient

and the normalised impedance of the termination represented by the lower case , subscript T

gives the result:

Alternatively, in terms of the reflection coefficient

These are the equations which are used to construct the  Smith chart. Mathematically speaking  and  are related via a Möbius transformation.

Both  and  are expressed in complex numbers without any units. They both change with frequency so for any particular measurement, the frequency at which it was performed must be stated together with the characteristic impedance.

 may be expressed in magnitude and angle on a polar diagram. Any actual reflection coefficient must have a magnitude of less than or equal to unity so, at the test frequency, this may be expressed by a point inside a circle of unity radius. The Smith chart is actually constructed on such a polar diagram. The Smith chart scaling is designed in such a way that reflection coefficient can be converted to normalised impedance or vice versa. Using the Smith chart, the normalised impedance may be obtained with appreciable accuracy by plotting the point representing the reflection coefficient treating the Smith chart as a polar diagram and then reading its value directly using the characteristic Smith chart scaling. This technique is a graphical alternative to substituting the values in the equations.

By substituting the expression for how reflection coefficient changes along an unmatched loss-free transmission line

for the loss free case, into the equation for normalised impedance in terms of reflection coefficient

and using Euler's formula

yields the impedance-version transmission-line equation for the loss free case:

where
 is the impedance 'seen' at the input of a loss free transmission line of length  terminated with an impedance

Versions of the transmission-line equation may be similarly derived for the admittance loss free case and for the impedance and admittance lossy cases.

The Smith chart graphical equivalent of using the transmission-line equation is to normalise  to plot the resulting point on a  Smith chart and to draw a circle through that point centred at the Smith chart centre. The path along the arc of the circle represents how the impedance changes whilst moving along the transmission line. In this case the circumferential (wavelength) scaling must be used, remembering that this is the wavelength within the transmission line and may differ from the free space wavelength.

Regions of the  Smith chart
If a polar diagram is mapped on to a cartesian coordinate system it is conventional to measure angles relative to the positive -axis using a counterclockwise direction for positive angles. The magnitude of a complex number is the length of a straight line drawn from the origin to the point representing it. The Smith chart uses the same convention, noting that, in the normalised impedance plane, the positive -axis extends from the center of the Smith chart at  to the point  The region above the x-axis represents inductive impedances (positive imaginary parts) and the region below the -axis represents capacitive impedances (negative imaginary parts).

If the termination is perfectly matched, the reflection coefficient will be zero, represented effectively by a circle of zero radius or in fact a point at the centre of the Smith chart. If the termination was a perfect open circuit or short circuit the magnitude of the reflection coefficient would be unity, all power would be reflected and the point would lie at some point on the unity circumference circle.

Circles of constant normalised resistance and constant normalised reactance
The normalised impedance Smith chart is composed of two families of circles: circles of constant normalised resistance and circles of constant normalised reactance. In the complex reflection coefficient plane the Smith chart occupies a circle of unity radius centred at the origin. In cartesian coordinates therefore the circle would pass through the points (+1,0) and (−1,0) on the -axis and the points (0,+1) and (0,−1) on the -axis.

Since both  and  are complex numbers, in general they may be written as:

with a, b, c and d real numbers.

Substituting these into the equation relating normalised impedance and complex reflection coefficient:

gives the following result:

This is the equation which describes how the complex reflection coefficient changes with the normalised impedance and may be used to construct both families of circles.

The  Smith chart
The  Smith chart is constructed in a similar way to the  Smith chart case but by expressing values of voltage reflection coefficient in terms of normalised admittance instead of normalised impedance. The normalised admittance  is the reciprocal of the normalised impedance , so

Therefore:

and

The  Smith chart appears like the normalised impedance, type but with the graphic nested circles rotated through 180°, but the numeric scale remaining in its same position (not rotated) as the  chart.

Similarly taking

for real  and  gives an analogous result, although with more and different minus signs:

The region above the -axis represents capacitive admittances and the region below the -axis represents inductive admittances. Capacitive admittances have positive imaginary parts and inductive admittances have negative imaginary parts.

Again, if the termination is perfectly matched the reflection coefficient will be zero, represented by a 'circle' of zero radius or in fact a point at the centre of the Smith chart. If the termination was a perfect open or short circuit the magnitude of the voltage reflection coefficient would be unity, all power would be reflected and the point would lie at some point on the unity circumference circle of the Smith chart.

Practical examples

A point with a reflection coefficient magnitude 0.63 and angle 60° represented in polar form as , is shown as point P1 on the Smith chart. To plot this, one may use the circumferential (reflection coefficient) angle scale to find the  graduation and a ruler to draw a line passing through this and the centre of the Smith chart. The length of the line would then be scaled to P1 assuming the Smith chart radius to be unity. For example, if the actual radius measured from the paper was 100 mm, the length OP1 would be 63 mm.

The following table gives some similar examples of points which are plotted on the Z Smith chart. For each, the reflection coefficient is given in polar form together with the corresponding normalised impedance in rectangular form. The conversion may be read directly from the Smith chart or by substitution into the equation.

Working with both the Z Smith chart and the Y Smith charts
In RF circuit and matching problems sometimes it is more convenient to work with admittances (representing conductances and susceptances) and sometimes it is more convenient to work with impedances (representing resistances and reactances). Solving a typical matching problem will often require several changes between both types of Smith chart, using normalised impedance for series elements and normalised admittances for parallel elements. For these a dual (normalised) impedance and admittance Smith chart may be used. Alternatively, one type may be used and the scaling converted to the other when required. In order to change from normalised impedance to normalised admittance or vice versa, the point representing the value of reflection coefficient under consideration is moved through exactly 180 degrees at the same radius. For example, the point P1 in the example representing a reflection coefficient of  has a normalised impedance of . To graphically change this to the equivalent normalised admittance point, say Q1, a line is drawn with a ruler from P1 through the Smith chart centre to Q1, an equal radius in the opposite direction. This is equivalent to moving the point through a circular path of exactly 180 degrees. Reading the value from the Smith chart for Q1, remembering that the scaling is now in normalised admittance,  gives . Performing the calculation

manually will confirm this.

Once a transformation from impedance to admittance has been performed, the scaling changes to normalised admittance until a later transformation back to normalised impedance is performed.

The table below shows examples of normalised impedances and their equivalent normalised admittances obtained by rotation of the point through 180°. Again, these may be obtained either by calculation or using a Smith chart as shown, converting between the normalised impedance and normalised admittances planes.

Choice of Smith chart type and component type
The choice of whether to use the Z Smith chart or the Y Smith chart for any particular calculation depends on which is more convenient. Impedances in series and admittances in parallel add while impedances in parallel and admittances in series are related by a reciprocal equation. If  is the equivalent impedance of series impedances and  is the equivalent impedance of parallel impedances, then

For admittances the reverse is true, that is

Dealing with the reciprocals, especially in complex numbers, is more time-consuming and error-prone than using linear addition. In general therefore, most RF engineers work in the plane where the circuit topography supports linear addition. The following table gives the complex expressions for impedance (real and normalised) and admittance (real and normalised) for each of the three basic passive circuit elements: resistance, inductance and capacitance. Using just the characteristic impedance (or characteristic admittance) and test frequency an equivalent circuit can be found and vice versa.

Using the Smith chart to solve conjugate matching problems with distributed components
Distributed matching becomes feasible and is sometimes required when the physical size of the matching components is more than about 5% of a wavelength at the operating frequency. Here the electrical behaviour of many lumped components becomes rather unpredictable. This occurs in microwave circuits and when high power requires large components in shortwave, FM and TV broadcasting.

For distributed components the effects on reflection coefficient and impedance of moving along the transmission line must be allowed for using the outer circumferential scale of the Smith chart which is calibrated in wavelengths.

The following example shows how a transmission line, terminated with an arbitrary load, may be matched at one frequency either with a series or parallel reactive component in each case connected at precise positions.

Supposing a loss-free air-spaced transmission line of characteristic impedance , operating at a frequency of 800 MHz, is terminated with a circuit comprising a 17.5  resistor in series with a 6.5 nanohenry (6.5 nH) inductor. How may the line be matched?

From the table above, the reactance of the inductor forming part of the termination at 800 MHz is

so the impedance of the combination () is given by

and the normalised impedance () is

This is plotted on the Z Smith chart at point P20. The line OP20 is extended through to the wavelength scale where it intersects at the point . As the transmission line is loss free, a circle centred at the centre of the Smith chart is drawn through the point P20 to represent the path of the constant magnitude reflection coefficient due to the termination. At point P21 the circle intersects with the unity circle of constant normalised resistance at
.
The extension of the line OP21 intersects the wavelength scale at , therefore the distance from the termination to this point on the line is given by

Since the transmission line is air-spaced, the wavelength at 800 MHz in the line is the same as that in free space and is given by

where  is the velocity of electromagnetic radiation in free space and  is the frequency in hertz. The result gives , making the position of the matching component 29.6 mm from the load.

The conjugate match for the impedance at P21 () is

As the Smith chart is still in the normalised impedance plane, from the table above a series capacitor  is required where

Rearranging, we obtain
.
Substitution of known values gives

To match the termination at 800 MHz, a series capacitor of 2.6 pF must be placed in series with the transmission line at a distance of 29.6 mm from the termination.

An alternative shunt match could be calculated after performing a Smith chart transformation from normalised impedance to normalised admittance. Point Q20 is the equivalent of P20 but expressed as a normalised admittance. Reading from the Smith chart scaling, remembering that this is now a normalised admittance gives

(In fact this value is not actually used). However, the extension of the line OQ20 through to the wavelength scale gives . The earliest point at which a shunt conjugate match could be introduced, moving towards the generator, would be at Q21, the same position as the previous P21, but this time representing a normalised admittance given by
.
The distance along the transmission line is in this case

which converts to 123 mm.

The conjugate matching component is required to have a normalised admittance () of
.
From the table it can be seen that a negative admittance would require an inductor, connected in parallel with the transmission line. If its value is , then

This gives the result

A suitable inductive shunt matching would therefore be a 6.5 nH inductor in parallel with the line positioned at 123 mm from the load.

Using the Smith chart to analyze lumped-element circuits
The analysis of lumped-element components assumes that the wavelength at the frequency of operation is much greater than the dimensions of the components themselves. The Smith chart may be used to analyze such circuits in which case the movements around the chart are generated by the (normalized) impedances and admittances of the components at the frequency of operation. In this case the wavelength scaling on the Smith chart circumference is not used. The following circuit will be analyzed using a Smith chart at an operating frequency of 100 MHz. At this frequency the free space wavelength is 3 m. The component dimensions themselves will be in the order of millimetres so the assumption of lumped components will be valid. Despite there being no transmission line as such, a system impedance must still be defined to enable normalization and de-normalization calculations and  is a good choice here as . If there were very different values of resistance present a value closer to these might be a better choice.

The analysis starts with a Z Smith chart looking into R1 only with no other components present. As  is the same as the system impedance, this is represented by a point at the centre of the Smith chart. The first transformation is OP1 along the line of constant normalized resistance in this case the addition of a normalized reactance of -j0.80, corresponding to a series capacitor of 40 pF. Points with suffix P are in the Z plane and points with suffix Q are in the Y plane. Therefore, transformations P1 to Q1 and P3 to Q3 are from the Z Smith chart to the Y Smith chart and transformation Q2 to P2 is from the Y Smith chart to the Z Smith chart. The following table shows the steps taken to work through the remaining components and transformations, returning eventually back to the centre of the Smith chart and a perfect 50 ohm match.

3D Smith chart

A generalization of the Smith chart to a three dimensional sphere, based on the extended complex plane (Riemann sphere) and inversive geometry, was proposed by Muller, et al in 2011.

The chart unifies the passive and active circuit design on little and big circles on the surface of a unit sphere, using a stereographic conformal map of the reflection coefficient's generalized plane. Considering the point at infinity, the space of the new chart includes all possible loads: The north pole is the perfectly matched point, while the south pole is the completely mismatched point.

The 3D Smith chart has been further extended outside of the spherical surface, for plotting various scalar parameters, such as group delay, quality factors, or frequency orientation. The visual frequency orientation (clockwise vs. counter-clockwise) enables one to differentiate between a negative / capacitance and positive / inductive whose reflection coefficients are the same when plotted on a 2D Smith chart, but whose orientations diverge as frequency increases.

See also
 Bode plot
 Nyquist plot
 Heyland–Ossanna circle diagram
 cis (mathematics)
 Transversal (instrument making)

References

Further reading
  (37 pages) (NB. Includes an early graphical depiction of something similar to a Smith chart decades before Mizuhashi, Volpert and Smith published their works.)
  (xiv+316 pages)

  (29 pages)

  (27 pages)

External links

  Non-commercial, interactive Smith Chart that looks best in Excel 2007+.
  Non-commercial, available for Windows, Mac, and Linux. Many Smith chart tutorial videos. No circuit size restrictions. Not limited to ladder circuits.
  Commercial and free Smith chart for Windows
  Free web based Smith Chart Educational tool available on GitHub.
  2D and 3D Smith chart generalized tool for active and passive circuits (free for academia/education).

Electrical engineering
Charts

Smith chart


The old Essex County Jail is located in the University Heights section of Newark, Essex County, New Jersey, United States. The jail is Essex County's oldest public building and a national landmark of value for its architectural and social history. The complex consists of about 20 structures of various size, age, and function ranging in date from the 1830s to 1930s. Collectively, they represent the evolution of American prison history over 100 years. For the quality of its architecture, its social history, and its links to the 1967 Newark Riots, this jail was added to the National Register of Historic Places on September 3, 1991.

The site has been abandoned since 1971 and remains property of the City of Newark.

Geography
The jail was originally located at the city's edge in a neighborhood of farms and factories, adjacent to the recently completed Morris Canal. The grounds are now located adjacent to the Norfolk Street station of the Newark Light Rail, which was built along the route of the former canal bed in the 1930s. Due to the urban environment and geography, the jail's various buildings are tightly crowded over 1.5 acres - originally with few green spaces between for inmate recreation.

History

English architect and social reformer John Haviland designed and built the jail in 1837 at the corner of Newark and New Streets. Haviland was an established prison architect at the time who was most notable for Eastern State Penitentiary, among other prison designs that emphasized prisoner reform over brutal punishment. The Morris Canal ran adjacent to the jail and formed the back of the property line. When the building was first built it was known as the Newark Street Jail. This jail replaced an earlier structure located at the corner of Broad and Walnut Streets at the present site of the Grace Episcopal Church.

Haviland's jail consisted of a two-story square building built of brick and local brownstone in the Greek Revival style. Behind this there rose a three story sandstone structure - measuring roughly 75 by 100 feet - with tiers of cells running down the center. This cell block functioned as a temporary holding facility while inmates awaited trial and conviction. After conviction, inmates moved to the state prison in Caldwell, built 1872 and now demolished. In 1890, and again in 1893, 1903, and 1907, Haviland's original building was expanded with multiple additions increasing the number of prison cells upwards of 300. However, actual inmates numbers were often closer to 500 due to severe overcrowding during events like the 1967 Newark Riots. The building was also updated to include running water and toilet facilities in each cell. The building served as Essex County's main jail until 1971 when a new jail was built. In 1991, scenes for the film Malcolm X were shot at the jail. In 2003, a fire devastated the Women's Wing built 1895, which is now in rubble. The property is currently unsecured, open to trespassers and urban explorers, and frequently featured in ruins photography.

Current Site Conditions

The building was severely damaged by fire in 2003. A new science park was planned for the site, but plans never left the drawing board. The design called for demolishing the entire structure, but the city's landmarks committee, which seeks to have the jail preserved, rejected the plan in 2010. The jail is rapidly decaying and many sections have already fallen down. In particular, The Warden's House, which dates from 1837, has partially collapsed due to lack of maintenance. Pending more detailed surveys, the other sections need to be stabilized before the structure is rehabilitated.

In July 2017, Rutgers Law School applied to de-register the facility from the National Register of Historic Places and the New Jersey Register of Historic Places; de-registering the site would allow demolition to go forward with no legal requirements for a feasibility study of possible reuses.

In spring 2018, a team of graduate students at Columbia University GSAPP researched the architectural and social history of this structure and set forth eleven proposals for the jail's reuse. This research became the subject of a spring 2019 design studio and exhibit in the Newark's Hahne's Building with funding from the Hanini Group, NJ Appleseed, and Newark Landmarks. This represents a first concrete step toward this structure's constructive reuse.

See also
National Register of Historic Places listings in Essex County, New Jersey
Old Essex County Jail This website documents all aspects of this site: social history, oral history, and current conditions.

Related Jails
The architect John Haviland was known as the "jailer to the world." He constructed several other jails nearby  in a series of jails, all with similar materials, construction, and design. As follows:
 Eastern State Penitentiary in Philadelphia (1821–29).
 New Jersey State Prison near Trenton (1832–6).
 Rebuilding of Western State Penitentiary near Pittsburgh (1833–36).
 The Tombs (Hall of Justice) in Lower Manhattan (1835–38, demolished 1902).
 Missouri State Penitentiary, Jefferson City, MO (1836). Closed in 2004.
 Berks County Jail, Reading, PA (1848).
 Lancaster County Jail, 625 E. King Street, Lancaster, PA (1851).
 Rhode Island State Penitentiary
 (Old) Allegheny County Jail, Pittsburgh, PA.
 Luzerne County Jail, Wilkes-Barre, Pennsylvania (circa 1850).

References

External links

Photo documentation and history of the abandoned jail
Pictures of the old Essex County Jail

Government buildings completed in 1837
Infrastructure completed in 1837
Buildings and structures in Newark, New Jersey
Historic American Buildings Survey in New Jersey
National Register of Historic Places in Newark, New Jersey
Stone houses in New Jersey
Defunct prisons in New Jersey
New Jersey Register of Historic Places
County government buildings in New Jersey
John Haviland buildings
1837 establishments in New Jersey

Old Essex County Jail


A unikernel is a computer program statically linked with the operating system code on which it depends. Unikernels are built with a specialized compiler that identifies the operating system services that a program uses and links it with one or more library operating systems that provide them. Such a program requires no separate operating system and can run instead as the guest of a hypervisor.

The unikernel architecture builds on concepts developed by Exokernel and Nemesis in the late 1990s.

Design

In a library operating system, protection boundaries are pushed to the lowest hardware layers, resulting in:
 a set of libraries that implement mechanisms such as those needed to drive hardware or talk network protocols;
 a set of policies that enforce access control and isolation in the application layer.

The library OS architecture has several advantages and disadvantages compared with conventional OS designs. One of the advantages is that since there is only a single address space, there is no need for repeated privilege transitions to move data between user space and kernel space.  Therefore, a library OS can provide improved performance by allowing direct access to hardware without having to transition between user mode and kernel mode (on a traditional kernel this transition consists of a single TRAP instruction and is not the same as a context switch). Performance gains may be realised by elimination of the need to copy data between user space and kernel space, although this is also possible with Zero-copy device drivers in traditional operating systems.

A disadvantage is that because there is no separation, trying to run multiple applications side by side in a library OS, but with strong resource isolation, can become complex. In addition, device drivers are required for the specific hardware the library OS runs on. Since hardware is rapidly changing this creates the burden of regularly rewriting drivers to remain up to date.

OS virtualization can overcome some of these drawbacks on commodity hardware. A modern hypervisor provides virtual machines with CPU time and strongly isolated virtual devices. A library OS running as a virtual machine only needs to implement drivers for these stable virtual hardware devices and can depend on the hypervisor to drive the real physical hardware. However, protocol libraries are still needed to replace the services of a traditional operating system.  Creating these protocol libraries is where the bulk of the work lies when implementing a modern library OS. Additionally, reliance on a hypervisor may reintroduce performance overheads when switching between the unikernel and hypervisor, and when passing data to and from hypervisor virtual devices.

By reducing the amount of code deployed, unikernels necessarily reduce the likely attack surface and therefore have improved security properties.

An example unikernel-based messaging client has around 4% the size of the equivalent code bases using Linux.

Due to the nature of their construction, it is possible to perform whole-system optimisation across device drivers and application logic, thus improving on the specialisation. For example, off-the-shelf applications such as nginx, SQLite, and Redis running over a unikernel have shown a 1.7x-2.7x performance improvement.

Unikernels have been regularly shown to boot extremely quickly, in time to respond to incoming requests before the requests time-out.

Unikernels lend themselves to creating systems that follow the service-oriented or microservices software architectures.

The high degree of specialisation means that unikernels are unsuitable for the kind of general purpose, multi-user computing that traditional operating systems are used for.  Adding additional functionality or altering a compiled unikernel is generally not possible and instead the approach is to compile and deploy a new unikernel with the desired changes.

See also

 Microkernel
 Container (virtualization)
 Rump kernel
 IncludeOS

References

External links

 History and business model; coverage of IncludeOS. (LWN.net)

Operating system kernels

Unikernel


The Microsoft Reaction Card, developed by Microsoft in 2002 by Joey Benedek and Trish Miner, is a method used to check the emotional response and desirability of a design or product. This method is commonly used in the field of software design.

Using this method involves a participant describing a design / product based on a list of 118 words. Each word is placed on a separate card. After viewing a design or product, the participant is asked to pick out the words they feel are relevant. The moderator then asks the participant to explain the reason for their selection.

References

 http://uxmatters.com/mt/archives/2010/02/rapid-desirability-testing-a-case-study.php - online source of information
 https://www.nngroup.com/articles/microsoft-desirability-toolkit/

Microsoft culture
Software testing

Microsoft reaction card method


Greater London is the administrative area of London, England, coterminous with the London region. It contains 33 local government districts: the 32 London boroughs, which forms the ceremonial county of Greater London; and the City of London, which forms a distinct ceremonial county. The Greater London Authority, its devolved governance body, is responsible for strategic local government across the region, whilst regular local government is the responsibility of the borough councils and the City of London Corporation.

The county of Greater London completely surrounds the City of London. The London region has an geographic area of  and a population of 9,002,488. The county of Greater London is only slightly smaller, with an area of  and a population of 8,889,375; the City of London has an area of  and a population of 8,583. The region is almost entirely urbanised and contains the majority of the Greater London Built-up area, which extends into Hertfordshire, Essex, Kent, Surrey, and Berkshire and has a population of 9,787,426. Neither the administrative area nor the region hold city status, but the boroughs of the City of London and City of Westminster do. The region was historically part of Middlesex, Essex, Surrey, Kent and Hertfordshire.

The River Thames is the defining geographic feature of the region, entering it near Hampton in the west and flowing east before exiting downstream of Dagenham. Several tributaries of the Thames flow through the region, but are now mostly culverted and form part of London's sewerage system. The land immediately north and south of the river is flat, but rises to low hills further away, notably Hampstead Heath, Shooter's Hill, and Sydenham Hill. The region's highest point is Westerham Heights (), part of the North Downs. In the north-east the region contains part of Epping Forest, an ancient woodland.

The City of London has had its own government since the Anglo-Saxon period. The first London-wide directly elected local government was the London County Council, established for the County of London in 1889, which covered the core of the urban area. In 1965 the county was abolished and replaced by Greater London, a two-tier administrative area governed by the Greater London Council, thirty-two London boroughs, and the Corporation of London. The Greater London Council was abolished in 1986, and its responsibilities largely taken over by the boroughs. The Greater London Authority was formed in 2000.

Administrative history

The term "Greater London" was used before it was established by statute in 1965. It referred to the Metropolitan Police District, the area served by the Metropolitan Water Board, the London Passenger Transport Area, and the area defined by the Registrar General as the "Greater London Conurbation". The term was also used for the Greater London Arterial Road Programme, devised between 1913 and 1916, and the Greater London Planning Region, devised in 1927, which occupied  and included 9 million people.

Proposals to expand the County of London

Although the London County Council (LCC) and County of London were created in 1889, the area did not cover all of London. London's built-up area, postal district, transport network and Metropolitan Police District, extended vastly beyond the boundaries of the new administrative county. Many of the LCC housing projects, including the vast Becontree Estates, were also outside its boundaries. The LCC pressed for an alteration in its boundaries soon after the end of the First World War, noting that within the Metropolitan and City Police Districts there were 122 housing authorities. A Royal Commission on London Government was set up to consider the issue. The LCC proposed a vast new area for Greater London, with a boundary somewhere between the Metropolitan Police District and the home counties. Protests were made at the possibility of including Windsor, Slough and Eton in the authority. The commission made its report in 1923, rejecting the LCC's scheme. Two minority reports favoured change beyond the amalgamation of smaller urban districts, including both smaller borough councils and a central authority for strategic functions. The London Traffic Act 1924 was a result of the commission. Reform of local government in the County of London and its environs was next considered by the Royal Commission on Local Government in Greater London, chaired by Sir Edwin Herbert, which issued the 'Herbert Report' after three years of work in 1960. The commission applied three tests to decide if a community should form part of Greater London: how strong is the area as an independent centre in its own right; how strong are its ties to London; and how strongly is it drawn outwards towards the country rather than inwards towards London.

Greater London is created

Greater London was created by the London Government Act 1963, which came into force on 1 April 1965, replacing the administrative counties of Middlesex and London, including the City of London, where the London County Council had limited powers, and absorbing parts of Essex, Hertfordshire, Kent and Surrey. Greater London originally had a two-tier system of local government, with the Greater London Council (GLC) sharing power with the City of London Corporation (governing the small City of London) and the 32 London Borough councils. The GLC was abolished in 1986 by the Local Government Act 1985. Its functions were devolved to the City Corporation and the London Boroughs, with some functions transferred to central government and joint boards. Greater London formed the London region in 1994.

Greater London Authority

The 1998 London referendum established a public will to recreate an upper tier of government to cover the region. The Greater London Authority, London Assembly and the directly elected Mayor of London were created in 2000 by the Greater London Authority Act 1999. In 2000, the outer boundary of the Metropolitan Police District was re-aligned to the Greater London boundary. The 2000 and 2004 mayoral elections were won by Ken Livingstone (L), who had been the final leader of the GLC. The 2008 and 2012 elections were won by Boris Johnson (C). The 2016 and 2021 elections were won by Sadiq Khan (L). London was covered by a single Parliamentary constituency in the European Parliament before Brexit.

Geography

Greater London includes the most closely associated parts of the Greater London Urban Area and their historic buffers and includes, in five boroughs, significant parts of the Metropolitan Green Belt which protects designated greenfield land in a similar way to the city's parks. The closest and furthest boundaries are with Essex to the northeast between Sewardstonebury next to Epping Forest and Chingford and with the Mar Dyke between Bulphan and North Ockendon. Greater London is also bounded by Hertfordshire to the north, Berkshire and Buckinghamshire to the west, Kent to the southeast and Surrey to the south and southwest. The highest point is Westerham Heights, in the North Downs and on the boundary with Kent, at .
Central government has implemented small boundary changes. The greatest were the 1969 transfers of Farleigh to Surrey and Knockholt to Kent. Others have included exchange of two Thames islands with Surrey and adjustments during the 1990s to parts of the boundaries of three boroughs near the M25. The only part of Greater London outside the motorway is North Ockendon, the furthest land unit from its centre. The majority of Greater London forms the London Low Emission Zone (LEZ) and the Ultra Low Emission Zone (ULEZ).

The London postal district does not cover all of Greater London.

Governance

Greater London Authority
Greater London is under the strategic local governance of the Greater London Authority (GLA). It consists of an elected assembly, the London Assembly, and an executive head, the Mayor of London.

The current Mayor (not to be confused with the Lord Mayor of London) is Sadiq Khan. He is scrutinised by the elected London Assembly, which may amend his annual budget (by two-thirds majority) but otherwise lacks the power to block his directives. The headquarters of the GLA, previously at City Hall in Southwark, moved to The Crystal in Newham in January 2022. The Mayor is responsible for Greater London's strategic planning and is required to produce or amend the London Plan each electoral cycle.

Mayor of London
The Mayor of London is a directly elected politician who, along with the London Assembly, is responsible for the strategic government of Greater London.

London Assembly

For elections to the London Assembly, London is divided into 14 constituencies, each formed from two or three boroughs. The City of London forms part of the City and East constituency.

UK Parliament

London is divided into 73 Parliamentary borough constituencies, formed from the combined area of several wards from one or more boroughs. Typically a borough is covered by two or three constituencies.

Status
The London Region does not have city status granted by the Crown. The Cities of London and Westminster within it have received formal city status. Despite this, Greater London is commonly regarded as a city in the general senses of a conurbation and a municipality. A Lord Lieutenant of Greater London is appointed for its area, excluding the City of London. For the purposes of the Lieutenancies Act 1997, this area is defined as a county.

The term "London" usually refers to region or to the conurbation, but not often to the ancient, tiny City of London. That small area is often referred to as "the City" or "the Square Mile" and it forms the main financial district. Archaically, the urbanised area of London was known as the Metropolis. In common usage, the terms "London" and "Greater London" are usually used interchangeably. Greater London is officially divided for some purposes, with varying definitions, into Inner London and Outer London. For some strategic planning purposes, it is divided into five sub-regions.

Local government

Greater London is divided into 32 London Boroughs, each governed by a London Borough council. The City of London has a unique government dating back to the 12th century and is separate from the county of Greater London, although is still part of the region served by the Greater London Authority.

All London Borough councils belong to the London Councils association. Three London Boroughs carry the honorific title of Royal Borough: Kensington and Chelsea, Kingston, and Greenwich. Within the City of London are the liberties of Middle Temple and Inner Temple.

Demography

With increasing industrialisation, London's population grew rapidly throughout the 19th and early 20th centuries, and it was the most populated city in the world until overtaken by New York in 1925. Its population peaked at 8,615,245 in 1939. There were an estimated 7,753,600 official residents in mid-2009.

London's wider metropolitan area has a population of between 12 and 13 million depending on the definition of that area. According to Eurostat, London has been the most populous city and metropolitan area of the European Union.

The region covers an area of 1,579 square kilometres. The population density is 4,761 people per square kilometre, more than ten times that of any other British region. In terms of population, London is the 25th largest city and the 17th largest metropolitan region in the world. It is ranked 4th in the world in the number of US dollar billionaires residing in the city. It ranks as one of the most expensive cities in the world, alongside Tokyo and Moscow.

Ethnic groups
In the 2001 UK Census, 71.15% of the population classed their ethnic group as White, including White British (59.79%), White Irish (3.07%) or "Other White" (8.29%, mostly Greek-Cypriot, Italian, Polish and Portuguese). 12.09% classed themselves as British Asian, including Indian, Pakistani, Bangladeshi and "Other Asian" (mostly Sri Lankan, Arab and other Southern Asian ethnicities). 10.91% classed themselves as Black British (around 6% as Black African, 4% as Black Caribbean, 0.84% as "Other Black"). 3.15% were of mixed race; 1.12% as Chinese; and 1.58% as other (mostly Filipino, Japanese, Korean, Vietnamese and other "British Orientals"). 21.8% of inhabitants were born outside the European Union. Irish people, from both the Republic of Ireland and Northern Ireland, number about 200,000, as do the Scots and Welsh combined.

In January 2005, a survey of London's ethnic and religious diversity claimed that there were more than 300 languages spoken and more than 50 non-indigenous communities with a population of more than 10,000. Figures from the Office for National Statistics show that in 2006 London's foreign-born population was 2,288,000 (31%), up from 1,630,000 in 1997. The 2001 UK Census showed that 27.1% of the population were born outside the UK, and a slightly higher proportion were classed as Non-White.

In the 2011 UK Census, 59.79% of the population classed their ethnic group as White, including White British (44.89%), White Irish (2.15%) or "Other White" (12.65%, mostly Greek-Cypriot, Italian, Polish, Spanish, Colombians and Portuguese). 18.49% classed themselves as British Asian, including Indian, Pakistani, Bangladeshi and "Other Asian" (mostly Sri Lankan, Arab and other Southern Asian ethnicities). 13.32% classed themselves as Black British (7% as Black African, 4.22% as Black Caribbean, 2.08% as "Other Black"). 4.96% were of mixed race; and 3.44% as other (mostly Filipino, Japanese, Korean, Vietnamese and other "British Orientals").

The table shows the top 21 countries of birth of residents in 2011. These figures do not give a fair indication of the total population of the specific ethnic groups associated with each country. For example, Londoners of Greek origin (from both Greece and Cyprus) number 300,000, since an organised Greek community has been established for nearly two centuries. The same can be said for Italian and French Londoners whose communities have been here for centuries (the French Embassy estimates there are between 300,000 and 400,000 French citizens living in the UK, with "a huge majority of them living in London"). Though a Polish community has existed in London since the late-Middle Ages, it was not significant in the 2001 Census but has grown significantly since 2004, when Poland joined the European Union and by June 2010; London had 122,000 Polish residents. The German-born population figure may be misleading, however, because it includes British nationals born to parents serving in the British armed forces in Germany.

London has been a focus for immigration for centuries, whether as a place of safety or for economic reasons. Huguenots, Eastern European Jews, Cypriots and East African Asians are examples of the former; Irish, Bangladeshis and West Indians came for new lives. The East End district around Spitalfields has been first home for several ethnic groups, which have subsequently moved elsewhere in London as they gained prosperity.

Population

The population of the current area of Greater London rose from about 1.1 million in 1801 (when only about 850,000 people were in the urban area, while 250,000 were living in villages and towns not yet part of London) to an estimated 8.6 million in 1939, but declined to 6.7 million in 1988, before starting to rebound in the 1990s.

By 2006, the population had recovered to the level of 1970 (and the level of population in the 1920s). It has now surpassed the previous 1939 peak, and is over 9 million.

Figures here are for Greater London in its 2001 boundaries. Figures before 1971 have been reconstructed by the Office for National Statistics based on past censuses to fit the 2001 boundaries. Figures from 1981 onward are mid-year estimates (revised in August 2007), which are more accurate than the censuses, known to underestimate the population of London.

Economy

This is a chart of trend of regional gross value added (GVA) of Inner London at current basic prices published (pp. 240–253) by Office for National Statistics with figures in millions of British pounds sterling.

Eurostat data shows the GDP of Inner London to be 232 billion euros in 2009 and per capita GDP of 78,000 euros.

This is a chart of trend of regional gross value added of Outer London at current basic prices published (pp. 240–253) by Office for National Statistics with figures in millions of British pounds sterling.

Eurostat data shows the GDP of Outer London to be 103 billion euros in 2009 and per capita GDP of 21,460 euros.

Religion

The largest religious groupings are Christian (48.4%), Muslim (8.4%), Hindu (8.0%), Jewish (1.8%), Sikh (1.5%), and Buddhist (1.0%), alongside those of no religion (21.7%). The United Kingdom has traditionally been Christian, and London has a large number of churches, particularly in the city. St Paul's Cathedral in the City and Southwark Cathedral south of the river are Anglican administrative centres, while the clerical head of the Church of England and the worldwide Anglican Communion, the Archbishop of Canterbury, has his main residence at Lambeth Palace in the London Borough of Lambeth.

Important national and royal ceremonies are shared between St Paul's and Westminster Abbey. The Abbey is not to be confused with nearby Westminster Cathedral, the largest Roman Catholic cathedral in England and Wales. Religious practice in London is lower than in any other part of the UK or Western Europe and is around seven times lower than American averages. Despite the prevalence of Anglican churches, weekly observance is low within that denomination, although in recent years church attendance, particularly at evangelical Anglican churches in London, has started to increase.

London is home to sizeable Hindu, Sikh, Buddhist, Muslim and Jewish communities. Many Muslims live in Tower Hamlets and Newham; the most important Muslim buildings are the East London Mosque in Whitechapel and the London Central Mosque on the edge of Regent's Park. London's large Hindu community is in the north-western boroughs of Harrow and Brent, the latter containing one of Europe's largest Hindu temples, BAPS Shri Swaminarayan Mandir London.

Sikh communities are in East and West London, particularly Southall in the western borough of Ealing, which is also home to the largest Sikh temple in the capital. The majority of British Jews live in London, with significant communities in Stamford Hill (the most Orthodox Jewish area outside New York City and Israel) and St. John's Wood, Golders Green, and Edgware in North London.

Education

Publicly funded education has been administered through 33 LEAs, which correspond to the City of London and the 32 London boroughs, since the 1990 enactment of the Education Reform Act 1988. From 1965 to 1990, 12 Inner London boroughs and the City of London were served by the Inner London Education Authority.

The introduction of comprehensive schools, directed by Circular 10/65 in 1965, was mostly followed in Greater London; however, 19 grammar schools have been retained in some Outer London boroughs, with Sutton having the most with five, followed by Bexley with four and others in five other boroughs. In these boroughs the state schools outperform the (relatively few) independent schools. In inner London, private schools always get the best results and are larger in number. At GCSE and A level, Outer London boroughs have broadly better results than Inner London boroughs.

At GCSE, the best borough is Kingston upon Thames, closely followed by Sutton. Both boroughs have selective schools, and get the top two average GCSE results in England for LEAs. Next is Kensington and Chelsea, the third best in England, then Redbridge, Hammersmith and Fulham, Bromley, Barnet and Harrow. Only ten boroughs have GCSE results under the England average, and some inner-London boroughs have surprisingly good results considering where they lie on the scale of deprivation, e.g. Lambeth. Overall at GCSE in 2009, Greater London had the best results for regions of England. Greater London is generally a prosperous region, and prosperous areas generally have good GCSE results. The City of London has no state schools, just two independent schools. Haringey and Kensington and Chelsea have the most people that pass no GCSEs.

At A-level, the average results for LEAs are disappointing compared to their good GCSE results. Although Kingston upon Thames gets the best GCSE results in England, at A-level it is not even above average. Sutton gets the best A-level results in London and in England. Three of the schools in the top four at A-level in London are in Sutton. It has only one independent school. The few other boroughs with above-average A-level results are Havering, Barnet, Bexley, Redbridge, and Ealing. The poor A-level results in many London boroughs is explained by the quantity of independent schools getting good A-level results. The state school system is often bypassed at age 16 by the more able pupils. Some London boroughs need more good sixth form colleges.

The region's 34 further education colleges are funded through the Skills Funding Agency and the Young People's Learning Agency. Large colleges include Kingston College, Havering College of Further and Higher Education, and Croydon College.

Universities

The University of London has 20 federated colleges and schools. The two main constituents of the University of London are (in order of total funding) University College London (UCL) and King's College London (KCL). Imperial College was part of the University of London until 2007, and is now an independent university. UCL, KCL and Imperial have very large research grants – some of the largest in England after Cambridge and Oxford, UCL and Imperial receive around £600 million each which is more than twice as much as any other in the region. The next largest institution by funding is Queen Mary University of London, followed by City, University of London. London is also home to the London School of Economics and Political Science (LSE), one of the few solely social science institutions in the world. Together with UCL and Imperial, they make up the London vertex of the Golden Triangle universities, the other institutions being Oxford and Cambridge. The region has many medical schools although these are part of other institutions such as UCL, KCL and Imperial. The Royal Veterinary College is based in Camden (with another site in North Mymms in Hertfordshire).

50% of students come from the region, and around 30% from other regions. Most students from other regions come from South East England, the East of England, and, to a lesser degree, South West England; the vast majority are from the south of England. Over 50% students native to the region stay in the region, with 15% going to South East England, 30% to either Scotland, Wales or the North East and around 5% go elsewhere. London is a draw for UK graduates from all over the UK.

Over 70% of UK students to graduate from the University of London remain in London; just under 15% go to the South-East, and just over 5% go to the East of England and 10% elsewhere.

Twin cities
The GLA has twin and sister city agreements with the following cities.

See also

 Geographical
 Central London
 Inner London
 Outer London
 London boroughs
 Greater London Urban Area
 London commuter belt
 Metropolitan Police District
 M25 motorway

 Political
 Mayor of London
 List of Lord Lieutenants of Greater London
 List of High Sheriffs of Greater London
 London Plan
 City of London

 Historical
 Metropolitan Board of Works
 County of London
 Greater London Council

 Others
 Global city
 Greater London Area War Risk Study
 Megacity
 Metropolis

Notes

References

External links

 Greater London Authority
 Greater London Online – London Community News, Information and Business Directory
 Greater London Business Community Directory

Geography of London
Metropolitan areas of England
NUTS 1 statistical regions of England
Ceremonial counties of England
Local government in London
Regions of England
Southern England
NUTS 1 statistical regions of the European Union
Interested parties in planning in England
Counties of England established in 1965

Greater London


Forbidden Valley is a valley to the south of Citadel Peak in the Hays Mountains of Antarctica. The valley drains east-northeast from Mount Crockett to Scott Glacier and is partly covered by glacier and moraine. It was visited in December 1987 by a United States Antarctic Research Program – Arizona State University geological party led by Edmund Stump. The mouth of the valley is blocked by a moraine which denies easy access, hence the name.

References

Valleys of the Ross Dependency
Amundsen Coast

Forbidden Valley


Charles-Jean Grandmougin (17 January 1850 – 28 April 1930) was a French poet and playwright. He lived in Paris. Two of his poems appeared in the third and final volume of Le Parnasse contemporain (1876). His poetry has been set as songs by composers including Fauré, Chaminade, Boulanger, Pierné and Bizet. He was more well known as a librettist and translator for operas and oratorios. He wrote the libretto for César Franck's opera Hulda, set in 11th-century Norway, and based on the play Lame Hulda (1858) by Norwegian writer Bjørnstjerne Bjørnson. He also wrote the libretto for La Vierge, an oratorio by Jules Massenet.

Major works
 Esquisse sur Richard Wagner (1873)
 Les Siestes, poems (1874)
 Prométhée, drame antique (1878)
 Le Tasse, symphonie dramatique (1878)
 Nouvelles Poésies (1880)
 Souvenirs d'Anvers (1881)
 Orphée, drame antique en vers (1882)
 Caïn, biblical drama in verse
 Poèmes d'amour (1884)
 Rimes de combat (1886)
 À pleines voiles, poems (1888)
 L'Enfant Jésus, mystère en 5 parties et en vers
 Le Christ, sacred drama in verse, couronné par l'Académie française (1892)
 L'Empereur, epic drama in verse, in 13 scenes (1893)
 De la Terre aux Étoiles, poems (1897)
 Visions chrétiennes, récits en vers (1899)
 Le Réveillon, drama in one act, in verse
 La Vouivre, poème franc-comtois
 Les Serfs du Jura, drama in verse
 Aryénis, drama in verse
 La Chanson du village
 Medjour, story of the supernatural
 Les Heures divines, poems (1894)
 La Forêt mystérieuse, booklet
 Le Naufrage de l'amour, poem
 Contes d'aujourd'hui, prose
 Terre de France, poem
 Contes en prose
 Dernières Promenades (1910)
 Les Sirènes (1911)

References

Johnson, Graham (2009). Gabriel Fauré: the songs and their poets, Guildhall School of Music and Drama (London, England), p. 120

External links
Johnson, Graham (2009). Gabriel Fauré: the songs and their poets, Guildhall School of Music and Drama (London, England), p.120
Gérard WALCH, Anthologie des poètes français contemporains, 1924.

1850 births
1930 deaths
French librettists
French opera librettists
19th-century French poets
People from Vesoul
French male poets
19th-century French dramatists and playwrights
French male non-fiction writers
19th-century French translators

Charles Grandmougin


The Royal Netherlands Air Force (RNLAF) is the air force of the Netherlands.

The Air Force was founded in the year 1913. The aerobatic display team was active from 1979 to 2019, named the Solo Display Team.

History

Origin in 1913
The Dutch Air Force started on 1 July 1913 at Soesterberg airfield with 4 pilots. When it started it only had 1 aircraft, the brik.

Only a few months later 3 French Farman HF.20.

But these airplanes where fast to old and was replaced with the Nieuport and Caudron.

World War I (1914-1918)
The Netherlands stayed neutral during World War I.

New airfields where build at Gilze-Rijen air base, Arnhem, Venlo and Vlissingen.

Between the wars
The Dutch goverment cut the defence budget for the army and the army was almost gone.

As political tensions in Europe increased in the late 1930s the goverment tried to rebuild the army in 1938.

World War II and the late 1940s
In August of 1939 the army was ready. But because of low budget the air force only operated

176 combat aircraft of the types:

 16 Fokker T.V
 36 Fokker D.XXI
 35 Fokker G.I
 7 Fokker D.XVII
 17 Douglas DB-8A-3N
 20 Fokker C.X
 33 Fokker C.V
 20 Koolhoven FK-51

In May of 1940 German troops invade the Netherlands. Within five days the Dutch Army was defeated by the luftwaffe.

All of the Brigade's bombers, along with 30 Fokker D.XXI and 17 Fokker G.I fighters where shot down; 2 D.XXI and 8 G.I where destroyed on the ground.

2 G.I where captured by the German forces.

1950s and 1960s

 The Spitfire Mk.IX was used by 322 Squadron RNLAF until 1954, but was replaced as new squadrons were established.
 The Gloster Meteor F Mk.IV was used by 322, 323, 324, 325, 326, 327 and 328 Squadrons from 1948–1957. Bases included Soesterberg and Leeuwarden.
 The Gloster Meteor F Mk.VIII was used by 322, 323, 324, 325, 326, 327 and 328 sqn from 1951–1958.
 CTL consisted of seven new strike squadrons (306, 311, 312, 313, 314, 315 and 316 sqn), all equipped with Republic F-84G Thunderjet's. These aircraft were supplied by the United States under the Mutual Defense Aid Program from 1952–1956. 311 was the first flying squadron to be stood up at Volkel on 1 May 1951.
 322, 323, 324, 325, 326 and 327 Sqn operated the Hawker Hunter F Mk.4 between 1955–1964, and 322, 324, 325 and 326 Sqn operated the Hawker Hunter F Mk.6 between 1957–1968.
 700, 701 and 702 Sqn operated the North American F-86K Sabre all-weather fighter between 1955–1964.
 306, 311, 312, 313, 314, 315 and 316 Sqn changed aircraft configuration from 1955–1970 as the Republic F-84F Thunderstreak and RF-84F Thunderflash became available.

Western New Guinea conflict
The Indonesian government claimed Western New Guinea following the end of the Second World War. The Dutch government considered the area Dutch territory. Negotiations over the country were conducted for years, but tensions grew until Indonesia broke diplomatic relations with the Netherlands at the end of the 1950s.

In response, in 1958, the Netherlands deployed military reinforcements to New Guinea, including an Air Force detachment for the air defense of the island Biak as there was evidence that Indonesia was infiltrating the island in advance of a military operation

 one Hawker Hunter Mk.4 air defence squadron;
 a radar navigation system at Biak, and;
 a reserve airstrip at Noemfoer.

The Dutch government deployed a squadron consisting of 12 Hawker Hunter Mk.4 AD fighters and two Alouette II SAR helicopters. They were transported to Southeast Asia by the Karel Doorman. One year later the Dutch government deployed another 12 Hawker Hunter Mk6 AD fighters; these aircraft carried more fuel and had a larger combat radius.

In August 1962 Indonesia was ready to attack New Guinea. Despite reinforcements the Dutch defences would be insufficient to withstand the coming attack. Therefore, and because of international political pressure the Dutch government was forced to agree to the peaceful surrender of New Guinea. Dutch forces were withdrawn from the territory.

Cold War era, 1960s, 1970s and later
During the cold war Dutch Air Force flying units were integrated in NATO's Second Allied Tactical Air Force tasked with defending northern West Germany against Warsaw Pact forces.

 306, 311, 312, 322 and 323 Sqn changed configuration again from 1962–1984 after the dual role F-104 Starfighter was introduced.
 313, 314, 315 and 316 Sqn switched over to the NF-5 Freedom Fighter from 1969–1991. The NF-5 was a development of the Canadair CF-5 fighter. Northrop incorporated some NF-5 features into the F-5E/F Tiger II.
 Since 1979 all RNLAF fast-jet squadrons (originally 306, 311, 312, 313, 314, 315, 316, 322 and 323) have operated the multi role F-16 Fighting Falcon.

Former Yugoslavia
In 1992 Ypenburg Air Base closed. After the USAF handed over their section of Soesterberg in September 1994, Soesterberg then became a RNLAF transport helicopter base with 298 Squadron

(CH-47D Chinook) and 300 Squadron (AS 532U2 Cougar Mk2 and SA 316 Alouette III) stationed at the base.

RNLAF F-16s participated in all operations over Yugoslavia from 1993: Deny Flight, including Deliberate Force in 1995 and ending with Operation Allied Force in 1999 from two bases in Italy. Initially from Villafranca AB in the north of Italy, later moving south to Amendola AB. During the operations over FRY RNLAF F-16s flew reconnaissance (306 Sqn detachments from Volkel AB were in theatre throughout the operations), enforced the Bosnian no-fly zone, dropped bombs on Udbina AB (1994), successfully dropped an unguided bomb on a moving Serb tank during the fall of Srebrenica (1995), and took part in Deliberate Force later in the summer of 1995.

Between 1994 and 1997 Dutch GCI personnel, along with Canadian GCI controllers, provided many hundreds of hours of fighter control and surveillance as integrated members of USAF/ANG Air Control Squadrons. In May 1999 during the Kosovo crisis a RNLAF F-16AM pilot Major Peter Tankink shot down a Yugoslavian MiG-29 with an AMRAAM, but the force was more recognized for its high bombing accuracy. Allied Force was also the operational debut for the upgraded F-16AM. Besides the CAP missions, offensive bombing and photo reconnaissance missions were flown. KDC-10 tankers refuelled allied aircraft over the Adriatic Sea, and C-130 Hercules transports flew daily sorties from Eindhoven AB to logistically support the operation. Dutch F-16s also dropped cluster bombs on Niš. In total, RNLAF aircraft flew 1,194 sorties during operation Allied Force, which is about 7.5% of the total 37,000 sorties flown.

Operation Enduring Freedom and NATO in Afghanistan
On 2 October 2002 a tri-national detachment of 18 Dutch, Danish and Norwegian F-16 ground attack aircraft and one Dutch KDC-10 tanker deployed to Manas Air Base in Kyrgyzstan in support of ground forces in Afghanistan as part of Operation Enduring Freedom. On 1 October 2003 the Dutch F-16 detachment returned to the Netherlands and the KDC-10 returned even earlier (1 April 2003). The RNLAF returned to Manas AB on 8 September 2004 with five F-16 and one KDC-10 in support of the presidential elections of Afghanistan. This time the aircraft flew under the NATO ISAF flag. On 24 March 2005 the whole Dutch detachment transferred from Manas AB to Kabul International Airport. A detachment of six AH-64D Apache helicopters were already stationed at Kabul International Airport from April 2004 until March 2005.

In February 2006 four Dutch F-16s were joined by four Royal Norwegian Air Force F-16s in a detachment known as the 1st Netherlands-Norwegian European Participating Forces Expeditionary Air Wing (1 NLD/NOR EEAW). This was a follow up of the participation with the Belgian Air Force.

As part of the expanded NATO ISAF mission in southern Afghanistan in August 2006, the Royal Netherlands Air Force had three CH-47D Chinook of 298 Sq stationed at Kandahar Airfield. On 12 November 2006 eight F-16s transferred from Kabul International Airport to Kandahar Airfield, Additionally, a detachment of six (later four) AH-64D Apache helicopters had been stationed of Tarin Kowt, Uruzgan province. The CH-47D Chinooks of 298 sq rotated with Cougars from 300 sq. All helicopters together with a few F-16s returned to the Netherlands in November 2010. The other four F-16s transferred from Kandahar Airfield to Mazar-e-Sharif International Airport in November 2011. The F-16 flight, providing Close Air Support for ground forces and Recce Flights (specialised in counter-ied's), ended their mission officially on 1 July 2014.

On 31 August 2006 a Royal Netherlands Air Force (Michael "Sofac" Donkervoort) pilot was killed when his plane crashed during a mission to support British ground troops in Helmand province.

On 7 December 2007 military use of Twente Air Base ceased. The aerodrome is now known as Enschede Airport Twente. Flying officially ended at Soesterberg Air Base on 12 November 2008. The last jet ever to take off was a Hellenic AF F-4E. The base formally closed on 31 December 2008. The 298th and 300th squadron have been moved to Gilze-Rijen Air Base. A part of the base remains in use as a glider field, however. Also, the former USAFE side will be in use by ground units Relocated from Kamp van Zeist and will be called "Camp New Amsterdam". Finally, the AF museum (Royal Netherlands Military Aviation Museum) returned to the base and will use most of the existing hangars.

2010s
In 2013 the Royal Netherlands Air Force provided Strategic Airlift Support with a KDC-10 in support of French operations in Mali.

The RNLAF was hit hard by the Dutch defence cuts after the 2008 financial crisis. 311 Squadron was disbanded in September 2012, leaving four squadrons of F-16s, and one DC-10 Transport Aircraft was disposed of.

In October 2014 the Netherlands Air Force joined the US and its Allies fighting ISIL, deploying eight F-16s (of which two are in reserve) to Jordan.

On 31 October 2014 323 Tactess squadron (F-16) disbanded and its aircraft and personnel were merged into 322 Squadron. The following Wednesday (5 November) the squadron reformed in the US as the RNLAF's first Joint Strike Fighter unit.

303 Squadron (Agusta Bell AB 412SP) provided search and rescue within Dutch Flight Information Region) until 1 January 2015 when the unit was disbanded.

As per 2017 the Air Defence – Quick Reaction Force of two F-16 fighters are integrated for Belgian, Dutch and Luxembourg airspace and rotated between Dutch and Belgian ADF squadrons.

Operation Inherent Resolve – Iraq & Syria
From 2014 The Royal Netherlands Air Force provided eight F-16s in support of the coalition fighting IS. The aircraft were initially deployed in Iraq and later Syria. The mission was handed over to the Belgian Air Force in July 2016 after more than 2100 missions were flown, with weapons used over 1800 times. The Royal Netherlands Air Force contributed extensively to the missions flown by the coalition forces and were in high demand.

Since 2017 RNLAF KDC-10 and C-130 Hercules are deployed to an airfield in the Middle East to assist the USA led coalition in Operation Inherent Resolve.

In January 2018 the Dutch F-16s returned to the Middle East for a year-long deployment.

Air Bases
In the country of the Netherlands there are 11 air bases. They are.
 Deelen Air Base
 Eindhoven Air Base
 Gilze-Rijen Air Base
 Leeuwarden Air Base
 Valkenburg Naval Air Base (closed)
 Air Operations Control Station Nieuw-Milligen
 Soesterberg Air Base (closed)
 Volkel Air Base
 De Peel Air Base (closed)
 Woensdrecht Air Base
 Ypenburg Air Base (closed)

Fleet

Related pages

 Netherlands Naval Aviation Service
 Solo Display Team
 Netherlands armed forces

Air forces
1913 establishments in Europe
Organizations based in the Netherlands

Royal Netherlands Air Force


Jurassic Park: The Ride is a water-based amusement ride. It is based on the Steven Spielberg movie Jurassic Park and Michael Crichton's novel. It is at Universal Studios Hollywood. The ride was researched and built while the movie was in its production phase.

The ride opened on June 21, 1996. Duplicates of the ride have since been built at Islands of Adventure and Universal Studios Japan. A river rapids ride version of the attraction, Jurassic Park Rapids Adventure, opened in Universal Studios Singapore in 2010.

Amusement rides

Jurassic Park: The Ride


Charles G. Case II is a Federal Bankruptcy Court Judge for the United States bankruptcy court, District of Arizona. He was appointed on January 5, 1994 and reappointed on January 5, 2009.

Education
Judge Case graduated cum laude from Harvard University with his Bachelor of Arts degree.  Later he graduated magna cum laude from Arizona State University College of Law with his Juris Doctor.

Legal career
From 1975 to 1988, Case practiced with the law firm of Lewis and Roca in Phoenix.  Before his appointment in 1994 he was a member of the Phoenix law firm of Meyer, Hendricks, Victor, Osborn & Maledon, P.A., where he concentrated in bankruptcy, Chapter 11 reorganizations, secured transactions and commercial litigation.

Positions and memberships
Case is a fellow of the American College of Bankruptcy and a member of the American Law Institute, the International Insolvency Institute, the International Exchange of Experience in Insolvency, and the American Bankruptcy Institute. He was also the President of the National Conference of Bankruptcy Judges and a former member of the Board of the Harvard Alumni Association.

External links
 District of Arizona bankruptcy court

References

Judges of the United States bankruptcy courts
Living people
Harvard University alumni
Sandra Day O'Connor College of Law alumni
Year of birth missing (living people)

Charles G. Case II


De Morgan or de Morgan is a surname, and may refer to:
Augustus De Morgan (1806–1871), British mathematician and logician.
 De Morgan's laws (or De Morgan's theorem), a set of rules from propositional logic.
 The De Morgan Medal, a triennial mathematics prize awarded by the London Mathematical Society.
 William De Morgan (1839–1917), English designer, potter, ceramics-worker, and novelist.
 Evelyn De Morgan (1855–1919), English pre-Raphaelite painter.
 Jacques de Morgan (1857–1924), French archaeologist.

De Morgan


Andrew, Duke of Slavonia (; 1268–1278) was the youngest son of King Stephen V of Hungary and his wife, Elizabeth the Cuman. Two rebellious lords kidnapped him in 1274 in an attempt to play him off against his brother, Ladislaus IV of Hungary, but the king's supporters liberated him. He was styled "Duke of Slavonia and Croatia" in a 1274 letter. Years after his death (in 1290 and in 1317), two adventurers claimed to be identical with Andrew, but both failed.

Family

Andrew was born in 1268. He was the second son (and youngest child) of Stephen V, the junior king of Hungary at the time of Andrew's birth. The senior king was Andrew's grandfather Béla IV. Andrew's mother was Stephen's wife, Elizabeth the Cuman.

Andrew's father, Stephen, became the sole King of Hungary in 1270, but died two years later. Stephen was succeeded by his elder son (Andrew's ten-year-old brother) Ladislaus IV. In theory, Ladislaus's ruled under the regency of his mother, Elizabeth, but in fact, competing parties of the most wealthy noble families, including the Csáks and Kőszegis, were fighting against each other for the control of government.

Duke of Slavonia

Henry Kőszegi, the Ban of Slavonia, and his ally, Joachim Gutkeled, the Master of the treasury, who had earlier held Ladislaus IV in captivity, kidnapped the six-year-old Andrew in July 1274, taking him to Slavonia in an attempt to play him off against his brother. However, Kőszegi's and Gutkeled's rival, Peter Csák, and his allies annihilated their united troops in late September and liberated Andrew.
 In a letter dated to the end of 1274, Andrew is mentioned as "Duke of Slavonia and Croatia", but otherwise he was only referred to as "Duke Andrew". According to a scholarly theory, the former title was only used to emphasize that Andrew was the lawful heir to his 12-year-old elder brother at the time the letter, which referred to a planned marriage between Andrew and a relative of Rudolf I of Germany, was written. Andrew died at the age of ten between 6 April and 6 November 1278.

Two false Andrews

Andrew's childless brother, Ladislaus IV was murdered on 10 July 1290. His distant relative, Andrew III, succeeded him and was crowned king on 23 July. However, an adventurer announced that he was identical with King Ladislaus's younger brother, claiming Hungary to himself against Andrew III. Through showing his specific birthmark, the impostor even convinced Stephen V's sisterthe late Duke Andrew's auntKinga, wife of Bolesław V the Chaste, Duke of Cracow. The false Duke Andrew invaded Hungary from Poland, but King Andrew's commander, George Baksa routed his troop, forcing him to return to Poland before 18 November. The pretender was in short killed by his Hungarian retainers.

In 1317, a new adventurer declared himself Duke Andrew, on this occasion in Majorca. He and his imprisonment was mentioned in the correspondence between Sancho, King of Majorca, and Robert, King of Naples who was the uncle of Charles I of Hungary. The second false Duke Andrew's further fate is unknown.

References

Sources

Dukes of Slavonia
House of Árpád
Hungarian princes
1268 births
1278 deaths
People of Cuman descent
Sons of kings
Royalty who died as children

Andrew, Duke of Slavonia


King Rajasinghe II, also known as Rajasingha II (pre coronation, Prince Deva Astana/Devarajasinghe), was a Sinhalese King, reigned 1629 – 6 December 1687; seventh king of the Kingdom of Kandy in Sri Lanka. Rajasingha requested Dutch aid to help expel the Portuguese from the island, which they successfully did in 1656. By this time however it had become clear to the Kandyans that the Dutch not only intended to expel the Portuguese but to replace them as the major colonial power on the island. This transfer of power is also believed to be where the Sinhala idiom / figure of speech "ඉඟුරු දී මිරිස් ගත්තා වාගේ" Inguru di miris gaththa wagay (Literal meaning: Like one exchanged ginger for chili) was originated - in reference that the Dutch Rule was much more of a menace to the king and cruel to the people in the island than the Portuguese. From 1645 onwards Rajasingha was engaged in sporadic warfare with his erstwhile allies.

Birth and early life
Rajasingha was the son of Senarat (Senarath), the second ruler of the kingdom of Kandy, based at the city of Senkadagala (modern Kandy) in Sri Lanka's mountainous interior. Since the Portuguese annexation of much of Sri Lanka's coastal areas the kingdom had represented the sole independent native polity on the island. Near incessant warfare had significantly embittered the Kandyans towards the Portuguese; furthermore the brief success of the warlike kingdom of Sitawaka a century earlier had convinced many in the kingdom that the total expulsion of the colonial power was a distinct possibility.

As a young man Rajasingha participated in the 1612 counteroffensive that routed a Portuguese invasion into Kandyan territory.

Rajasingha succeeded his father to the throne in 1634 (1629 in some sources)

Early reign: arrival of the Dutch

Rajasingha's father had long courted the Dutch as a potential ally against the Portuguese. A treaty had been signed between Kandy and Dutch envoy Marcelis Boschouwer but had not amounted to much. Soon after Rajasingha's accession however the Dutch, now firmly established in Batavia, put Portuguese Goa under a blockade. On 28 March 1638, Rajasingha led his army to victory against the Portuguese forces at Gannoruwa. Soon after this, Rajasingha sent a request for aid to the admiral Adam Westerwolt and by 23 May 1638 had signed an extensive military and trade treaty with them.
The Dutch seized Batticaloa on 18 May 1639 and a joint Kandyan–Dutch campaign began to make inroads into Portugal's lowland territories. The alliance was however deeply unpopular with the inhabitants of Kandy.

Tensions soon arose between the two parties. Batticaloa was the traditional port of the Kandyan kingdom (Trincomalee had long been lost, first to the Jaffna kingdom and then to the Portuguese), and Rajasingha was eager to acquire it as soon as possible. The Dutch, however, demurred, demanding full payment for their assistance in displacing the Portuguese. Despite a rising suspicion that the Dutch were not in Sri Lanka to expel the Portuguese, so much as to replace them, the alliance was one that was too valuable for Rajasingha to simply cancel, and joint Dutch–Kandyan efforts resulted in the seizure of Galle on 13 March 1640 and the restriction of Portuguese power to the west coast of Sri Lanka by 1641.

The slow end of the Eighty Years' War however soon resulted in a truce being called between Dutch and Portuguese forces in Sri Lanka (the crowns of Spain and Portugal were united between 1580–1640) sometime between 1641 and 1645. Rajasinga, and many of his advisers, furiously concluded that the Dutch intended to carve Sri Lanka up with the Portuguese, to the detriment of native power. The alliance of 1638 came to an abrupt end and Kandy launched into what was to be a hundred years of intermittent warfare with the Dutch.

The period between 1645 and 1649 saw the Kandyan adopting a scorched earth policy in eastern Sri Lanka. Capturing and annexing Dutch held territory was out of the question for the Kandyans who could muster neither the firepower nor the manpower for an occupation. Nevertheless, Rajasingha's policy of intentionally burning crops and depopulation villages drove the Dutch to the negotiating table and in 1649 and the Kandyan-Dutch alliance was resurrected, albeit on slightly different terms.

Late reign: stalemate

Despite the resurrection of the treaty tensions remained between the Dutch and the Kandyans. The Treaty of Münster had secured Dutch independence in Europe in 1648 and they could now pursue colonial and mercantile expansion without fighting a ruinous war on their doorstep simultaneously. In contrast the kingdom of Kandy was exhausted by constant war, and still without access to Batticaloa, Trincomalee, and the lowlands. Furthermore, it had limited resources, and was increasingly wracked by internal instability.

Nevertheless, from 1652 joint Kandyan-Dutch forces waged an increasingly brutal war against Portuguese strongholds along the coast. During this time Rajasingha had to request support from the sub-king — Patabanda — of Koggala, which suggests that the Kandyan kingdom had by this time become very decentralised, and that local leaders held considerable power.

The landlocked Kandyans were successful in the inland area of the Korales and Sabaragamuwa but relied heavily on Dutch sea power. Accordingly, in August 1655 a large Dutch fleet commanded by Gerard Pietersz. Hulft arrived and the war entered its final phase with the siege by land and sea of the Portuguese colonial capital Colombo. By this point Rajasingha did not trust the Dutch at all and insisted that the city should be ceded to the Kandyan the moment it fell. When this happened in 1656, however, the Dutch shut the gates and left the Kandyans in the hinterlands. Faced with what he saw as yet another example of Dutch perfidy, Rajasingha repeated his devastations of the mid-1640s in the hinterlands of Colombo and withdrew to Kandy. The Dutch in the meanwhile secured power over the kingdom of Jaffna in 1658 and essentially replaced the Portuguese as Kandy's natural enemy on the island.

Safe in his mountain fastness Rajasingha now adopted the same tactics he had deployed against the Portuguese to harass the Dutch. In 1660 his army is known to have been in the vicinity of Dutch-held Trincomalee, and seized the Englishman Robert Knox. Knox subsequently moved to Senkadagala and lived there until 1679; his writings provide one of the best sources on the Kandyan kingdom in the 17th century. Rajasingha may also have considered involving the French in Sri Lankan politics in an attempt to get yet another European power to displace the Dutch.

In Kandy, Rajasingha faced discontented nobles and a populace who had always been opposed to the alliance with the Dutch. The internal situation became so unstable that for a while Rajasingha was forced to abandon the palace and allow rebels to seize control of Sengkadagala, and even suspended the annual Perahara. In 1664, he faced open rebellion from a noble known as Ambanwela Rala, and, unable in his fury to think of a suitable punishment, sent him to the Dutch, assuming they would execute him as a Kandyan noble. It was a mistake — Ambanwela Rala traded his knowledge of the workings of Kandy for a large coconut estate in Dutch territory and died a rich man.

Despite this the king managed to retain control of the crown and expanded the sacred precinct of Kandy, the Dalada Maligawa, adding an extra storey to the central building.

Significance

The single most important trend of Rajasingha's long reign was the replacement of the Portuguese by the Dutch. The strategy of bringing in one European power to help fend off another had backfired spectacularly, and the Kandyan kingdom found itself in much the same position as it had been with the Portuguese. Despite the Dutch being less determined to convert the mass populace and impose their cultural dominance, Europeans increasingly came to be seen as rapacious adventurers who were simply incapable of honouring their deals.

The situation inside the Kandyan kingdom became increasingly unstable and during Rajasingha's reign many of the powerful families that came to dominate Kandyan politics in the 18th century acquired greater power. Attempts on Rajasingha's life appear to have been rather commonplace. Rajasingha's reign also saw a gradual diminution of the Kandyans' dreams of reuniting Sri Lanka under a single, native, crown.

See also
 List of Sri Lankan monarchs
 Mahavamsa
 History of Sri Lanka

Sources

 Kings & Rulers of Sri Lanka

External links
 Lanka Library - Rajasinghe2

R
1687 deaths
Monarchs of Kandy
1608 births
R
R

Rajasinha II of Kandy