Catuvellauni

Before the second expedition, Mandubracius of the Trinovantes sought Roman assistance after Cassivellaunus, a ruler associated with the Catuvellauni, had overthrown his father. Caesar restored Mandubracius, while Cassivellaunus eventually agreed to provide hostages and annual tribute and to leave the Trinovantes in peace. This established a useful precedent: a displaced British ruler could invite Roman intervention.