Caratacus (Brythonic *Caratācos, Middle Welsh Caratawc; Welsh Caradog; Breton Karadeg; Greek Καράτακος; variants Latin Caractacus, Greek Καρτάκης) was a 1st-century AD British chieftain of the Catuvellauni tribe, who resisted the Roman conquest of Britain.
Before the Roman invasion, Caratacus is associated with the expansion of his tribe's territory. His apparent success led to Roman invasion, nominally in support of his defeated enemies. He resisted the Romans for almost a decade, mixing guerrilla warfare with set-piece battles, but was unsuccessful in the latter. After his final defeat 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.
The legendary Welsh character Caradog ap Bran and the legendary British king Arvirargus may be based upon Caratacus. Caratacus's speech to Claudius has been a common subject in art.
Caratacus's name appears as both Caratacus and Caractacus in manuscripts of Tacitus, and as Καράτακος and Καρτάκης in manuscripts of Dio. Older reference works tend to favour the spelling "Caractacus", but modern scholars agree, based on historical linguistics and source criticism, that the original Common Brittonic form was *Karatākos, pronounced karaˈtaːkos, cognate with Welsh Caradog, Breton Karadeg, and Irish Carthach, meaning "loving, beloved, dear; friend".
Caratacus is named by Dio Cassius as a son of the Catuvellaunian king Cunobelinus. Based on coin distribution Caratacus appears to have been the protégé of his uncle Epaticcus, who expanded Catuvellaunian power westwards most likely from his palace in Verulam, the heartland of the Catuvellauni, into the territory of the Atrebates. After Epaticcus died in about AD 35, the Atrebates, under Verica, regained some of their territory, but it appears Caratacus completed the conquest, as Dio tells us Verica was ousted, fled to Rome and appealed to the emperor Claudius for help.