Caratacus was a first century British chieftain of the Catuvellauni tribe, who led the British resistance to the Roman conquest.
Caratacus's fighting technique included conventional battlefield warfare (which he was unsuccessful at) and guerrilla fighting (which he was successful at). After his final defeat (the site of which is lost to history) he fled to the territory of Queen Cartimandua, who captured him and handed him over to the Romans. He was sentenced to death as a military prisoner, but made a speech before his execution that persuaded the Emperor Claudius to spare him. He lived out the remainder of his life in Rome, and his death is unrecorded.
Playwright John Fletcher used Caratacus, under the name of Caratach in his 1613 play Boudica. In his novel Ruled Britannia, Harry Turtledove heavily cribbed from Flether's play, even including Caratacus/Caratach.