In the military of ancient Rome, decimation was a form of military discipline in which every tenth man in a group was executed by members of his cohort. The discipline was used by senior commanders in the Roman army to punish units or large groups guilty of capital offences, such as cowardice, mutiny, desertion, and insubordination, and for pacification of rebellious legions. The procedure was an attempt to balance the need to punish serious offences with the realities of managing a large group of offenders.
Decimation. Etching by William Hogarth in Beaver's Roman Military Punishments (1725)
Capital punishment, also known as the death penalty and formerly called judicial homicide, is the state-sanctioned practice of killing a person as a punishment for a crime, usually following an authorised, rule-governed process to conclude that the person is responsible for violating norms that warrant said punishment. The sentence ordering that an offender be punished in such a manner is known as a death sentence, and the act of carrying out the sentence is known as an execution. A prisoner who has been sentenced to death and awaits execution is condemned and is commonly referred to as being "on death row". Etymologically, the term capital refers to execution by beheading, but executions are carried out by many methods, including hanging, shooting, lethal injection, stoning, electrocution, and gassing.
Anarchist Auguste Vaillant about to be guillotined in France in 1894
The Christian Martyrs' Last Prayer, by Jean-Léon Gérôme (1883). Roman Circus Maximus.
The Death of Socrates (1787), in the Metropolitan Museum of Art in New York City
The breaking wheel was used during the Middle Ages and was still in use into the 19th century.