Decapitation
Decapitation, or beheading, is killing a person by cutting their head off. This may be done by hand with an axe, sword, or knife, or by guillotine. In rare cases it may be also be the result of an explosion, being driven over by a train, etc.
Separation of the head from the rest of the body is a criterion for death, there is no hope of survival.
Decapitation has been used as a form of capital punishment for millennia. The modern legal terminology capital offence or capital crime, as well as the term capital punishment itself, derives from the punishment for qualifying serious offences having been the removal of one's head. Political prisoners (labelled traitors) and serious criminals often had their heads removed and placed on public display for a period of time. On the other hand, execution by beheading with a sword could be at times considered an "honorable" way to die for an aristocrat, who, presumably being a warrior, could generally expect to die by the sword in any event. This would be distinguished from a "dishonorable" death on the gallows or through burning at the stake.
If the headsman's axe or sword was sharp and his aim was true, decapitation was a quick and relatively painless form of death. If the instrument was blunt or the execution clumsy, however, it was considerably more painful. The culprit was therefore advised to give a gold coin to the headsman so that he did his job with care.
Decapitation by sword has in modern times occurred in jurisdictions subject to Islamic Sharia, and by militant Islamists.
Decapitation by guillotine was a common form of execution invented shortly before the French Revolution (although an earlier version of the guillotine, the gibbet, was used in England until the 17th century). The aim was that only one form of execution, involving no torture, should exist. It was used in France until 1977.
The use of decapitation has been discontinued in part because of suspicion that the severed head may in certain cases continue to be alive to some extent and be able to feel pain. Some evidence for that was gathered by studying presence of death-related chemicals in the brains of beheaded animals. There have also been many more or less apocryphal stories in France about the severed heads of guillotined persons that would change face expression or move their lips. Certainly another major reason for the end of the practice of beheading is the violent and messy nature of the practice.
It is of note that in the biblical Book of Revelation beheading is named as a method of execution of Christian martyrs during a great persecution (Rev. 20:4). There is no historical record of such an event, so most commentators believe that this verse refers to the last great persecution of the church that is expected to occur shortly before the Second Coming of Christ.
Some famous people who have been beheaded
Modern era: