 Caesar besieged him there and brought him to terms.When Caesar left Britain he took hostages from the Britons, although which tribes were compelled to give any is not specified.The archaeologists Graham Webster and Barry Cunliffe both agree that nothing more is known about them, but it has been suggested that between Caesar's second invasion and the invasion of Claudius in AD 43 that the Cassi along with other tribes such as the Ancalites and Bibroci merged to form the Catuvellauni, and that Cassivellaunus may have been a member of the Cassi tribe.