Vigilantism is the act of preventing, investigating and punishing perceived offenses and crimes without legal authority.
The "Bald Knobbers", an 1880s vigilante group from Missouri – as portrayed in the 1919 film The Shepherd of the Hills
An outlaw, in its original and legal meaning, is a person declared as outside the protection of the law. In pre-modern societies, all legal protection was withdrawn from the criminal, so anyone was legally empowered to persecute or kill them. Outlawry was thus one of the harshest penalties in the legal system. In early Germanic law, the death penalty is conspicuously absent, and outlawing is the most extreme punishment, presumably amounting to a death sentence in practice. The concept is known from Roman law, as the status of homo sacer, and persisted throughout the Middle Ages.
A statue of Robin Hood, a heroic outlaw in English folklore
Henry Danvers, Earl of Danby, was outlawed in 1597 by a coroner's court for the murder of Henry Long. He went to France and joined the French Army; two years later, he was pardoned by Queen Elizabeth I and returned to England.
Napoleon on the Bellerophon. Napoleon Bonaparte on HMS Bellerophon after his surrender to the British in 1815