King Herod Agrippa, that is, Herod Agrippa II, was the son of Herod Agrippa I (Acts ch. 12). He possessed the tetrarchies of Philip and Lysanias (Lk 3:1) with the title of king.
He was the last king from the family of the Herods, with whom this royal line came to an end. Being in vassal relations to Rome, he considered it his duty to congratulate Festus on his new appointment.
For this purpose, soon after Festus entered the office of procurator of Judea, Agrippa came to Caesarea. Wishing to show courtesy to his guest, Festus proposed that Herod hear Paul's case.
Herod confessed the same Jewish faith and was therefore more able to understand this case than he, the Roman procurator. For, as Festus observed, Paul's accusers disputed with him over certain questions of their worship (verses 13-27).