 Emissaries of five British tribes, including the Bibroci (the others being the Ancalites, the Segontiaci, the Cenimagni and the Cassi), arrived at the Roman camp to treat for peace, and agreed to reveal details of Cassivellaunus' stronghold.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.