This fort is one of the traditional sites of the last stand of Caractacus, ‘King of the Britons’, against the invading Romans. He was also known as Caradoc. Having regrettably lost the fight he was taken with his family to Rome – but apparently not to the unpleasant fate you might imagine for him: it seems the Emperor respected his reputation and spared him.
(Reader’s Digest ‘Folklore Myths and Legends of Britain’)