Who is Caractacus and Togodumnus from Claudius the God and His Wife Messalina and what is their importance?

Brothers, Caractacus and Togodumnus, rule Britain together. Togodumnus' haughty command to Claudius is what begins the war between Rome and Britain. During the war, Togodumnus is killed in battle, after which, all of the troops come together under Caractacus command. Caractacus is later caputured by the Romans and delivered to Rome, where he stands trial. Claudius grants scapes but is eventually captured and taken to Rome. During his trial, Caractacushis mercy.