You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Decapitation and explain in detail?
Decapitation or beheading is the total separation of the head from the body. Such an injury is invariably fatal to humans and most other animals, since it deprives the brain of oxygenated blood, while all other organs are deprived of the involuntary functions that are needed for the body to function.
The term beheading refers to the act of deliberately decapitating a person, either as a means of murder or as an execution; it may be performed with an axe, sword, knife, machete or by mechanical means such as a guillotine or chainsaw. An executioner who carries out executions by beheading is sometimes called a headsman. Accidental decapitation can be the result of an explosion, a car or industrial accident, improperly administered execution by hanging or other violent injury. Suicide by decapitation is rare but not unknown. The national laws of Saudi Arabia, Yemen, and Qatar permit beheading; however, in practice, Saudi Arabia is the only country that continues to behead its offenders regularly as a punishment for capital crime.Less commonly, decapitation can also refer to the removal of the head from a body that is already dead. This might be done to take the head as a trophy, for public display, to make the deceased more difficult to identify, for cryonics, or for other, more esoteric reasons.

Etymology
The word decapitation has its roots in the Late Latin word decapitare. The meaning of the word decapitare can be discerned from its morphemes de- (down, from) + capit- (head). The past participle of decapitare is decapitatus which was used to create decapitationem, the noun form of decapitatus in Medieval Latin. From the Medieval Latin form, decapitationem, the French word décapitation was produced.

History
Humans have practiced capital punishment by beheading for millennia. The Narmer Palette (c. 3000 BCE) shows the first known depiction of decapitated corpses. The terms "capital offence", "capital crime", "capital punishment", derive from the Latin caput, "head", referring to the punishment for serious offences involving the forfeiture of the head; i.e. death by beheading.Some cultures, such as ancient Rome and Greece regarded decapitation as the most honorable form of death. In the Middle Ages, many European nations continued to reserve the method only for nobles and royalty. In France, the French Revolution made it the only legal method of execution for all criminals regardless of class, one of the periods many symbolic changes.Others have regarded beheading as dishonorable and contemptuous, such as the Japanese troops who beheaded prisoners during World War II. In recent times, it has become associated with terrorism.

Physiological aspects
Pain
If the headsmans axe or sword was sharp and his aim was precise, decapitation was quick and is presumed to be a relatively painless form of death. If the instrument was blunt or the executioner was clumsy, repeated strokes might be required to sever the head, resulting in a prolonged and more painful death. The person to be executed was therefore advised to give a gold coin to the headsman to ensure that he did his job with care. Robert Devereux, 2nd Earl of Essex, and Mary, Queen of Scots required three strikes at their respective executions. The same could be said for the execution of Johann Friedrich Struensee, favorite of the Danish queen Caroline Matilda of Great Britain. Margaret Pole, 8th Countess of Salisbury, is said to have required up to 10 strokes before decapitation was achieved. This particular story may, however, be apocryphal (since highly divergent accounts exist). Historian and philosopher David Hume, for example, relates the following about her death:She refused to lay her head on the block, or submit to a sentence where she had received no trial. She told the executioner, that if he would have her head, he must win it the best way he could: and thus, shaking her venerable grey locks, she ran about the scaffold; and the executioner followed her with his axe, aiming many fruitless blows at her neck before he was able to give the fatal stroke.
To ensure that the blow would be fatal, executioners swords usually were blade-heavy two-handed swords. Likewise, if an axe was used, it almost invariably was wielded with both hands. In England a bearded axe was used for beheading, with the blades edge extending downwards from the tip of the shaft.Finlands official beheading axe resides today at the Museum of Crime in Vantaa. It is a broad-bladed two-handed axe. It was last used when murderer Tahvo Putkonen was executed in 1825, the last execution in peacetime in Finland.

Physiology of death by decapitation
Decapitation is quickly fatal to humans and most animals. Unconsciousness occurs within 10 seconds without circulating oxygenated blood (brain ischemia). Cell death and irreversible brain damage occurs after 3–6 minutes with no oxygen, due to excitotoxicity. Some anecdotes suggest more extended persistence of human consciousness after decapitation, but most doctors consider this unlikely and consider such accounts to be misapprehensions of reflexive twitching rather than deliberate movement, since deprivation of oxygen must cause nearly immediate coma and death ("[Consciousness is] probably lost within 2–3 seconds, due to a rapid fall of intracranial perfusion of blood").A laboratory study testing for humane methods of euthanasia in awake animals used EEG monitoring to measure the time duration following decapitation for rats to become fully unconscious, unable to perceive distress and pain. It was estimated that this point was reached within 3–4 seconds, correlating closely with results found in other studies on rodents (2.7 seconds, and 3–6 seconds). The same study also suggested that the massive wave which can be recorded by EEG monitoring approximately one minute after decapitation ultimately reflects brain death. Other studies indicate that electrical activity in the brain has been demonstrated to persist for 13 to 14 seconds following decapitation (although it is disputed as to whether such activity implies that pain is perceived), and a 2010 study reported that decapitation of rats generated responses in EEG indices over a period of 10 seconds that have been linked to nociception across a number of different species of animals, including rats.Some animals (such as cockroaches) can survive decapitation, and die not because of the loss of the head directly, but rather because of starvation. A number of other animals, including snakes, and turtles, have also been known to survive for some time after being decapitated, as they have a slower metabolism, and their nervous systems can continue to function at some capacity for a limited time even after connection to the brain is lost, responding to any nearby stimulus. In addition, the bodies of chickens and turtles may continue to move temporarily after decapitation.Although head transplantation by the reattachment of blood vessels has seen some very limited success in animals, a fully functional reattachment of a severed human head (including repair of the spinal cord, muscles, and other critically important tissues) has not yet been achieved.

Technology
Guillotine
Early versions of the guillotine included the Halifax Gibbet, which was used in Halifax, England, from 1286 until the 17th century, and the "Maiden", employed in Edinburgh from the 16th through the 18th centuries.
The modern form of the guillotine was invented shortly before the French Revolution with the aim of creating a quick and painless method of execution requiring little skill on the part of the operator. Decapitation by guillotine became a common mechanically assisted form of execution.
The French observed a strict code of etiquette surrounding such executions. For example, a man named Legros, one of the assistants at the execution of Charlotte Corday, was imprisoned for three months and dismissed for slapping the face of the victim after the blade had fallen in order to see whether any flicker of life remained. The guillotine was used in France during the French Revolution and remained the normal judicial method in both peacetime and wartime into the 1970s, although the firing squad was used in certain cases. France abolished the death penalty in 1981.
The guillotine was also used in Algeria before the French relinquished control of it, as shown in Gillo Pontecorvos film The Battle of Algiers.
Another guillotine existed in Vatican City until recent years. It had been brought in by Napoleons forces during the early 19th century; and, as of 1870, the pope still claimed the authority to use it. The Holy See has since abolished capital punishment within its own jurisdiction, and recent popes have condemned capital punishment wherever it is still practised.

German Fallbeil
Many German states had used a guillotine-like device known as a Fallbeil ("falling axe") since the 17th and 18th centuries, and decapitation by guillotine was the usual means of execution in Germany until the abolition of the death penalty in West Germany in 1949. It was last used in communist East Germany in 1966.
In Nazi Germany, the Fallbeil was reserved for common criminals and people convicted of political crimes, including treason. Members of the White Rose resistance movement, a group of students in Munich that included siblings Sophie and Hans Scholl, were executed by decapitation.
Contrary to popular myth, executions were generally not conducted face up, and chief executioner Johann Reichhart was insistent on maintaining "professional" protocol throughout the era, having administered the death penalty during the earlier Weimar Republic. Nonetheless, it is estimated that some 16,500 persons were guillotined in Germany and Austria between 1933 and 1945, a number that includes resistance fighters both within Germany itself and in countries occupied by Nazi forces. As these resistance fighters were not part of any regular army, they were considered common criminals and were in many cases transported to Germany for execution. Decapitation was considered a "dishonorable" death, in contrast to execution by firing squad.

Historical practices by nation
Africa
Congo
In the Democratic Republic of Congo, the conflict and ethnic massacre between local army and Kamuina Nsapu rebels has caused several deaths and atrocities such as rape and mutilation. One of them is decapitation, both a fearsome way to intimidate victims as well as an act that may include ritualistic elements. According to an UN report from Congolese refugees, they believed the Bana Mura and Kamuina Nsapu militias have "magical powers" as a result of drinking the blood of decapitated victims, making them invincible. According to some reports, they indeed feed the blood from their victims heads to younger members as an initiation rite, then they often burn the remains or sometimes consume these, committing cannibalism.Besides the massive decapitations (like the beheading of 40 members of the State Police), a globally notorious case happened in March 2017 to Swedish politician Zaida Catalán and American UN expert Michael Sharp, who were kidnapped and executed during a mission near the village of Ngombe in Kasaï Province. The UN was reportedly horrified when video footage of the executions surfaced in April that same year, where some grisly details led to assume ritual components of the beheading: the perpetrators first cut the hair of both victims, and then one of them beheaded Catalán only, because it would "increase his power", which may be linked to the fact that Congolese militias are particularly brutal in their acts of violence toward women and children.In the trial that followed investigations after the bodies were discovered, and according to a testimony of a primary school teacher from Bunkonde, near the village of Moyo Musuila where the executions took place, he witnessed a teenage militant carrying the young womans head, but despite the efforts of the investigation, the head was never found. According to a report published on 29 May 2019, the Monusco peacekeeping military mission led by Colonel Luis Mangini, in the search for the missing remains, arrived to a ritual place in Moyo Musila where "parts of bodies, hands and heads" were cut and used for rituals, where they lost track of the victims head.

Asia
Azerbaijan
During the 2016 Armenian–Azerbaijani clashes, reports emerged that Yazidi-Armenian serviceman, Kyaram Sloyan, was decapitated by the Azerbaijani servicemen. Azerbaijan denied this.Several reports of decapitation, along with other types of mutilation of the Armenian POWs by Azerbaijani soldiers emerged during the 2020 Nagorno-Karabakh war.

China
In traditional China, decapitation was considered a more severe form of punishment than strangulation, although strangulation caused more prolonged suffering. This was because in Confucian tradition, bodies were gifts from their parents, and so it was therefore disrespectful to their ancestors to return their bodies to the grave dismembered. The Chinese however had other punishments, such as dismembering the body into multiple pieces (similar to the English quartering). In addition, there was also a practice of cutting the body at the waist, which was a common method of execution before being abolished in the early Qing dynasty due to the lingering death it caused. In some tales, people did not die immediately after decapitation.

India
The British officer John Masters recorded in his autobiography that Pathans in British India during the Anglo-Afghan Wars would behead enemy soldiers who were captured, such as British and Sikh soldiers.

Japan
In Japan, decapitation was a common punishment, sometimes for minor offences. Samurai were often allowed to decapitate soldiers who had fled from battle, as it was considered cowardly. Decapitation was historically performed as the second step in seppuku (ritual suicide by disembowelment). After the victim had sliced his own abdomen open, another warrior would strike his head off from behind with a katana to hasten death and to reduce the suffering. The blow was expected to be precise enough to leave intact a small strip of skin at the front of the neck—to spare invited and honored guests the indelicacy of witnessing a severed head rolling about, or towards them; such an occurrence would have been considered inelegant and in bad taste. The sword was expected to be used upon the slightest sign that the practitioner might yield to pain and cry out—avoiding dishonor to him and to all partaking in the privilege of observing an honorable demise. As skill was involved, only the most trusted warrior was honored by taking part. In the late Sengoku period, decapitation was performed as soon as the person chosen to carry out seppuku had made the slightest wound to his abdomen.
Decapitation (without seppuku) was also considered a very severe and degrading form of punishment. One of the most brutal decapitations was that of Sugitani Zenjubō (杉谷善住坊), who attempted to assassinate Oda Nobunaga, a prominent daimyō, in 1570. After being caught, Zenjubō was buried alive in the ground with only his head out, and the head was slowly sawn off with a bamboo saw by passers-by for several days (punishment by sawing; nokogiribiki (鋸挽き). These unusual punishments were abolished in the early Meiji era. A similar scene is described in the last page of James Clavells book Shōgun.

Korea
Historically, decapitation had been the most common method of execution in Korea, until it was replaced by hanging in 1896. Professional executioners were called mangnani (망나니) and they were volunteered from death-rows.

Pakistan
Pakistans government employs death by hanging for capital punishment. Since 2007, militants from Tehrek-e-Taliban Pakistan have used beheadings as a form of punishment for opponents, criminals and spies in the north west region of Pakistan. Severed heads of opponents or government officials in Swat Valley were left on popular street corners in order to terrorize local population. The beheadings have stopped in Swat since the military incursion and sweep-up that began in May 2009 and ended in June 2009. Three Sikhs were beheaded by the Taliban in Pakistan in 2010. Daniel Pearl was beheaded by his captors in the city of Karachi.
Despite official condemnation from the state itself, such beheading continues to flourish in the Taliban strongholds of Baluchistan and Khyber-Pakhtunkhwa.

Thailand
Historically, decapitation had been the main method of execution in Thailand, until it was replaced by shooting in 1934.

Europe
Bosnia and Herzegovina
During the war in Bosnia and Herzegovina (1992–1995) there were a number of ritual beheadings of Serbs and Croats who were taken as prisoners of war by mujahedin members of the Bosnian Army. At least one case is documented and proven in court by the ICTY where mujahedin, members of 3rd Corps of Army BiH, beheaded Bosnian Serb Dragan Popović.

Britain
In British history, beheading was typically used for noblemen, while commoners would be hanged; eventually, hanging was adopted as the standard means of non-military executions. The last actual execution by beheading was of Simon Fraser, 11th Lord Lovat on 9 April 1747, while a number of convicts (typically traitors were sentenced to be hanged, drawn and quartered, a method which had already been discontinued) were beheaded posthumously up to the early 19th century. Beheading was degraded to a secondary means of execution, including for treason, with the abolition of drawing and quartering in 1870 and finally abolished by the Statute Law (Repeals) Act 1973. One of the most notable executions by decapitation in Britain was that of King Charles I of England, who was beheaded outside the Banqueting House in Whitehall in 1649, after being captured by parliamentarians during the English Civil War.

Celts
The Celts of western Europe long pursued a "cult of the severed head", as evidenced by both Classical literary descriptions and archaeological contexts. This cult played a central role in their temples and religious practices and earned them a reputation as head hunters among the Mediterranean peoples. Diodorus Siculus, in his 1st-century Historical Library (5.29.4) wrote the following about Celtic head-hunting:

They cut off the heads of enemies slain in battle and attach them to the necks of their horses. The blood-stained spoils they hand over to their attendants and striking up a paean and singing a song of victory; and they nail up these first fruits upon their houses, just as do those who lay low wild animals in certain kinds of hunting. They embalm in cedar oil the heads of the most distinguished enemies, and preserve them carefully in a chest, and display them with pride to strangers, saying that for this head one of their ancestors, or his father, or the man himself, refused the offer of a large sum of money. They say that some of them boast that they refused the weight of the head in gold.
Both the Greeks and Romans found the Celtic decapitation practices shocking and the latter put an end to them when Celtic regions came under their control. However, Greeks and Romans both employed decapitation and other horrific tortures, highlighting a tendency to view practices as more shocking when carried out by an outside group, even if the practices are essentially similar.According to Paul Jacobsthal, "Amongst the Celts the human head was venerated above all else, since the head was to the Celt the soul, centre of the emotions as well as of life itself, a symbol of divinity and of the powers of the other-world." Arguments for a Celtic cult of the severed head include the many sculptured representations of severed heads in La Tène carvings, and the surviving Celtic mythology, which is full of stories of the severed heads of heroes and the saints who carry their own severed heads, right down to Sir Gawain and the Green Knight, where the Green Knight picks up his own severed head after Gawain has struck it off in a beheading game, just as Saint Denis carried his head to the top of Montmartre.A further example of this regeneration after beheading lies in the tales of Connemaras Saint Féchín, who after being beheaded by Vikings carried his head to the Holy Well on Omey Island and on dipping it into the well placed it back upon his neck and was restored to full health.

Classical antiquity
The ancient Greeks and Romans regarded decapitation as a comparatively honorable form of execution for criminals. The traditional procedure, however, included first being tied to a stake and whipped with rods. Axes were used by the Romans, and later swords, which were considered a more honorable instrument of death. Those who could verify that they were Roman citizens were to be beheaded, rather than undergoing the much more horrific experience of crucifixion. In the Roman Republic of the early 1st century BC, it became the tradition for the severed heads of public enemies—such as the political opponents of Marius and Sulla, for example—to be publicly displayed on the Rostra in the Forum Romanum after execution. Perhaps the most famous such victim was Cicero who, on instructions from Mark Antony, had his hands (which had penned the Philippicae against Antony) and his head cut off and nailed up for display in this manner.

France
In France, until the abolition of capital punishment in 1981, the main method of execution had been by beheading by means of the guillotine. Other than a small number of military cases in which a firing squad was used (including that of Jean Bastien-Thiry), the guillotine was the only legal method of execution from 1791, when it was introduced by the Legislative Assembly during the last days of the kingdom French Revolution, until 1981. Before the revolution, beheading had typically been reserved for noblemen and carried out manually. In 1981, President François Mitterrand abolished capital punishment and issued commutations for those whose sentences had not been carried out.
The first person executed by the guillotine in France was highwayman Nicolas Jacques Pelletier in April 1792. The last execution was of murderer Hamida Djandoubi, in Marseilles, in 1977. Throughout its extensive overseas colonies and dependencies, the device was also used, including on St Pierre in 1889 and on Martinique as late as 1965.

Germany
Fritz Haarmann, a serial killer from Hannover who was sentenced to death for killing 27 young men, was decapitated in April 1925. He was nicknamed "The Butcher from Hannover" and was rumored to have sold his victims flesh to his neighbors restaurant.
In July 1931, notorious serial killer Peter Kürten, known as "The Vampire of Düsseldorf", was executed on the guillotine in Cologne.
On 1 August 1933, in Altona, Bruno Tesch and three others were beheaded. These were the first executions in Nazi Germany. The executions concerned the Altona Bloody Sunday (Altonaer Blutsonntag) riot, an SA march on 17 July 1932 that turned violent and led to 18 people being shot dead.
Marinus van der Lubbe by guillotine in 1934 after a show trial in which he was found guilty of starting the Reichstag fire.
In February 1935 Benita von Falkenhayn and Renate von Natzmer were beheaded with the axe and block in Berlin for espionage for Poland. Axe beheading was the only method of execution in Berlin until 1938, when it was decreed that all civil executions would henceforth be carried out by guillotine. However, the practice was continued in rare cases such as that of Olga Bancic and Werner Seelenbinder in 1944. Beheading by guillotine survived in West Germany until 1949 and in East Germany until 1966.
A group of three Catholic clergymen, Johannes Prassek, Eduard Müller and Hermann Lange, and an Evangelical Lutheran pastor, Karl Friedrich Stellbrink, were arrested following the bombing of Lübeck, tried by the Peoples Court in 1943 and sentenced to death by decapitation; all were beheaded on 10 November 1943, in the Hamburg prison at Holstenglacis. Stellbrink had explained the raid next morning in his Palm Sunday sermon as a "trial by ordeal", which the Nazi authorities interpreted to be an attack on their system of government and as such undermined morale and aided the enemy.
In October 1944, Werner Seelenbinder was executed by manual beheading, the last legal use of the method (other than by guillotine) in both Europe and the rest of the Western world. Earlier the same year, Olga Bancic had been executed by the same means.
In February 1943, American academic Mildred Harnack and the university students Hans Scholl, Sophie Scholl, and Christoph Probst of the White Rose protest movement, were all beheaded by the Nazi State. Four other members of the White Rose, an anti-Nazi group, were also executed by the Peoples Court later that same year. The anti-Nazi Helmuth Hübener was also decapitated by Peoples Court order.
In 1966, former Auschwitz doctor Horst Fischer was executed by the German Democratic Republic by guillotine, the last executed by this method outside France. Beheading was subsequently replaced by shooting in the neck.

Nordic countries
In Nordic countries, decapitation was the usual means of carrying out capital punishment. Noblemen were beheaded with a sword, and commoners with an axe. The last executions by decapitation in Finland in 1825, Norway in 1876, Faroe Islands in 1609, and in Iceland in 1830 were carried out with axes. The same was the case in Denmark in 1892. Sweden continued the practice for a few decades, executing its second to last criminal—mass murderer Johan Filip Nordlund—by axe in 1900. It was replaced by the guillotine, which was used for the first and only time on Johan Alfred Ander in 1910.
The official beheading axe of Finland resides today in the Museum of Crime, Vantaa.

Spain
In Spain executions were carried out by various methods including strangulation by the garrotte. In the 16th and 17th centuries, noblemen were sometimes executed by means of beheading. Examples include Anthony van Stralen, Lord of Merksem, Lamoral, Count of Egmont and Philip de Montmorency, Count of Horn. They were tied to a chair on a scaffold. The executioner used a knife to cut the head from the body. It was considered to be a more honourable death if the executioner started with cutting the throat.

Middle East
Iran
Iran, since the 1979 Islamic Revolution, has alleged it uses beheading as one of the methods of punishment.

Iraq
Though not officially sanctioned, legal beheadings were carried out against at least 50 prostitutes and pimps under Saddam Hussein as late as 2000.Beheadings have emerged as another terror tactic especially in Iraq since 2003. Civilians have borne the brunt of the beheadings, although U.S. and Iraqi military personnel have also been targeted. After kidnapping the victim, the kidnappers typically make some sort of demand of the government of the hostages nation and give a time limit for the demand to be carried out, often 72 hours. Beheading is often threatened if the government fails to heed the wishes of the hostage takers. Sometimes, the beheadings are videotaped and made available on the Internet. One of the most publicized of such executions was that of Nick Berg.Judicial execution is practiced in Iraq, but is generally carried out by hanging.

Saudi Arabia
Saudi Arabia has a criminal justice system based on Shariah law reflecting a particular state-sanctioned interpretation of Islam. Crimes such as rape, murder, apostasy, and sorcery are punishable by beheading. It is usually carried out publicly by beheading with a sword.
A public beheading will typically take place around 9am. The convicted person is walked into the square and kneels in front of the executioner. The executioner uses a sword to remove the condemned persons head from his or her body at the neck with a single strike. After the convicted person is pronounced dead, a police official announces the crimes committed by the beheaded alleged criminal and the process is complete. The official might announce the same before the actual execution. This is the most common method of execution in Saudi Arabia.According to Amnesty International, at least 79 people were executed in Saudi Arabia in 2013. Foreigners are not exempt, accounting for "almost half" of executions in 2013.

Syria
The Syrian government employs hanging as its method of capital punishment. However, the terrorist organisation known as the Islamic State, which controlled territory in much of eastern Syria, had regularly carried out beheadings of people. Syrian rebels attempting to overthrow the Syrian government have been implicated in beheadings too.

North America
Mexico
Miguel Hidalgo y Costilla, Ignacio Allende, José Mariano Jiménez and Juan Aldama were tried for treason, executed by firing squad and beheaded during the Mexican independence in 1811. Their heads were on display on the four corners of the Alhóndiga de Granaditas, in Guanajuato.
During the Mexican Drug War, some Mexican drug cartels turned to decapitation and beheading of rival cartel members as a method of intimidation.
 This trend of beheading and publicly displaying the decapitated bodies was started by the Los Zetas, a criminal group composed by former Mexican special forces operators, trained in the infamous US Army School of the Americas, in torture techniques and psychological warfare.

United States
The United States government has never employed beheading as a legal method of execution. However, beheading has sometimes been used in mutilations of the dead, particularly of black people like Nat Turner, who led a rebellion against slavery. When caught, he was publicly hanged, flayed, and beheaded. This was a technique used by many enslavers to discourage the "frequent bloody uprisings" that were carried out by "kidnapped Africans"