Julius Caesar was now master of Rome, and Pompey was an exile. Cæsar released Aristobulus from prison. He gave him two legions and sent him to Syria, that he might conquer that country and the sections adjoining Judea. But the partisans of Pompey poisoned the king, and his gallant son, Alexander, was beheaded by Scipio at Antioch at the command of Pompey.
After Pompey's death, Antipater, who was ever on the alert to turn circumstances to his own advantage, cultivated the friendship of Cæsar, as he had done that of Pompey. He aided Mithridates, king of Pergamus, in his march towards Egypt to help Cæsar in that war which he waged in favor of Cleopatra. Mithridates was refused a passage through Pelusium, but, with the aid of Antipater and his army, he took Pelusium, and marched on until he was stopped again by those Egyptian Jews who lived in that part called the country of Onias. But Antipater persuaded them not only to let the army pass, but also to give him aid and provisions; on which account the people about Memphis would not fight against Mithridates, but joined him of their own accord. A great battle was fought against the remainder of the Egyptians at a place called the Jews' Camp. Mithridates would have been beaten had it not been for the bravery of Antipater, who led the left wing of the army. After defeating those that opposed him, he returned, and, falling upon the rest of the Egyptian forces, who had routed Mithridates, put them to flight.
Cæsar encouraged Antipater to undertake other dangerous enterprises for him; and, when he had settled the affairs of Egypt, he rewarded Antipater by giving him the right of Roman citizenship, freedom from taxes, and by making Hyrcanus high-priest.
Antigonus, the son of Aristobulus, came at this time to Cæsar and accused Antipater and Hyrcanus of injustice and extravagance, and said that such assistance as Antipater had given Cæsar was not on account of good will, but to gain pardon for formerly aiding Pompey. Upon this Antipater threw away his garments and declared that the wounds upon his body showed his good will to Cæsar, and that Antigonus only wished to obtain the government that he might stir up sedition against the Romans, as his father did before him. When Cæsar heard this he declared Hyrcanus to be most worthy of the high-priesthood. And he made Antipater procurator of all Judea, granting him leave to rebuild such walls in his country as had been overthrown. Antipater returned to Judea, rebuilt the walls of Jerusalem, and went over the country persuading the Jews to submit to the new government. But, as he found Hyrcanus to be weak and inactive, he managed the affairs of the kingdom himself, and appointed his elder son, Phasael, to the government of Jerusalem, and his younger son, Herod, to that of Galilee.
This Herod was a very active young man, and immediately won renown by capturing and killing a band of robbers that had been the terror of the country. Phasael also distinguished himself by his management of affairs in Jerusalem, so that Judea rang with the praises of these young men, and great honors were paid to Antipater.
Some of the Jews, jealous of Antipater and his sons, represented to Hyrcanus that these men were the real lords of Judea, and that they had robbed him of his authority. They persuaded the weak king that Herod had broken the law by executing the robbers without trial. Hyrcanus therefore summoned Herod to Jerusalem for trial. But Sextus Cæsar, a kinsman of the great Julius, and president of Syria, who loved Herod, sent word to Hyrcanus that Herod should be acquitted, and so he was set free. Herod went to join Sextus Cæsar in Damascus, and was made by him general of Celesyria and Samaria. Herod was very angry because he had been summoned to Jerusalem, so he got together an army and set out to overthrow Hyrcanus, but he was persuaded by Antipater and Phasael to give up his design.