Their connexion was highly unpopular at Rome, and Octavian (see Augustus) declared war upon them and defeated them at Actium (31 B.C.).
He first appears in history in 40 B.C., when he was employed by Octavian in arranging his marriage with Scribonia, and afterwards in assisting to negotiate the peace of Brundusium and the reconciliation with Antony.
A year later Octavian restored to the Jewish kingdom Jericho, Gadara, Hippos, Samaria, Gaza Anthedon, Joppa and Straton's Tower (Caesarea).
The senate of Rome under the influence of Antony and Octavian ratified the claims of Herod, and after some delay lent him the armed force necessary to make them good.
Antony repeatedly made Athens his headquarters and granted her several new possessions, including Eretria and Aegina - grants which Octavian subsequently revoked.
The Italian primate, Octavian de Palatio, knew better, and incurred the wrath of Kildare by refusing to officiate at the impostor's coronation.
In the war between Antony and Octavian Cleopatra prevented Herod from joining Antony and so left him free to pay court to Octavian after Actium (31 B.C.).
The controlling authority, which Octavian himself wielded, could not indeed be safely dispensed with.
On arriving in Italy he found that Octavian was already victorious; on the death of Fulvia, a reconciliation was effected between the triumvirs, and cemented by the marriage of Antony with Octavia, the sister of his colleague.
In 40 he helped to arrange the peace of Brundisium by which Octavian (Augustus) and Antonius were for a time reconciled.