Who is Herod Agrippa from Claudius the God and His Wife Messalina and what is their importance?

Whe he is first sent to Rome, Herod Agrippa is a young, Jewish orphan who is sent to the city after the death of his parents. He and Claudius' were friends as children. During his youth, Agrippa wanders from place to place without income, borrowing money to pay off his debts. He is arrested when he and Caligula are overheard discussing treasonous plots against Tiberius. Tiberius, however, is killed shortly after Agrippa's imprisonment, and Caligula releases him. After Caligula dies, Claudius gives Agrippa control over all of Judaea, Samaria and Edom.