Caratacus
A historical personage: Son of Cunobelinus (Cunobel) and brother of Togodumnus and the King of the Catuvellani, a tribe of early Britons who lived in the vicinity of modern-day St. Albans, at the time of the Roman invasion of Britain in AD 43.
He led a hard-fought anti-Roman campaign against the Roman invaders from his stronghold with the support of two Welsh tribes - the Silures and the Ordovices, but was eventually handed over to his foes by Cartimandua, Queen of the Brigantes. He was then pardoned by the Emperor Claudius after he had been taken to Rome.
E. Ratcliffe argues that the stories of Caratacus became misplaced in folklore and that he was the original Arthur. A similar argument is advanced by J. Whitehead. Both Ratcliffe and I.H. Elder regard Caratacus as identical with Arviragus, while E.R. Capt avers that he was Arviragus's cousin.