CASSIVELAUNUS, or CASSIVELAAUNUS  , a British chieftain, ruler df the country north of the Thames, who led the native tribes against Julius Caesar on his second expedition (54 B.c.) (see BRITAIN) . After several indecisive engagements, Caesar took the camp of Cassivelaunus, who was obliged to make peace on condition of paying tribute and giving hostages . But these promises were not meant to be kept, and it appears certain that the tribute was never paid . According to Bede (Hist . Eccles. i . 2), the remains of Cassivelaunus's entrenchment were visible seven or eight centuries later . See Caesar, B.G. v . 11-22; Dio Cassius xl . 2, 3; Orosius vi . 9 . 6; Eutropius vi . 17; Polyaenus, Strategemata, viii .

23 . For the

etymology of the name (which is Celtic in origin, and appears later as Caswallon) see J . Rhys, Celtic Britain, pp . 289-290 (1904); C . I . Elton, Origins of English History (189o) ; and Stock's edition of Caesar, De Bello Gallico (1898) .