40 BC had started out as very bad year for Herod. First, the Parthians had seen that Rome, and in particular, Marcus Antonius, who was dallying with Cleopatra, were paying little attention to the affairs of Judea. In this power vacuum, the Parthians had invaded Judea and quickly gained Jewish military support. After a short siege of Jerusalem, the Parthians had installed Antigonius as King. Antigonius had based his claim upon the throne on a policy of direct opposition to Rome. This and a large quantity of money as a bribe to the Satrap, Barzaphranes, one of the Parthian leaders was enough to induce the Parthians to back Antigonius as king. Thereafter, Jerusalem had revolted against Herod and his brother, Phasel.
Herod, Hyrcanus, and Phasel were ultimately bottled up in the Palace. Phasel learned that Antigonius had bought the throne. Upon the inducement of the cup bearer of Antigonius, Pacorus, Phasel with Hyrcanus went to Barzaphranes to negotiate a peaceful settlement and what he thought was a much bigger bribe. Barzaphranes did not succumb to the bribe and Phasel, now knowing his life was in danger, got a message to Herod. Herod fled Judea for Petra where he attempted to raise money to ransom his brother. When he was unsuccessful, he went to Alexandria. Thereafter, Phasel submitted to the Parthian leader, Barzaphranes, but was induced to commit suicide. Hyrcanus was disfigured and exiled.
In Alexandria, Cleopatra offered Herod a commission to lead her armies against the Parthians, but Herod declined the offer. As mentioned before, it was during the mid-winter of 40 BC that Herod left Alexandria for Rome.
In Rome, Herod brought the terrible news that the Parthians had conquered Judea. This first-hand account of the conquest by Judea by the Parthians, the fall of Judea, the misfortune that had befallen Herod’s family, and the installation of Antigonius as King roused Rome to action. Herod had played his hand well, for the Senate, perhaps unlike Marcus Antonius and Octavian, clearly saw the matter as an invasion of a Rome ally-client-state by an enemy. Antigonius was therefore an enemy. With both Hyrcanus and Phasel out of the picture, Herod became the only choice for Rome.
Herod’s choice of direct and forceful opposition to Parthia was thus one of his greatest decisions. For without having made this decision, he would not have been a candidate for the kingship in the eyes of Rome. Rome felt it needed a local force to oppose Parthia. Herod, with his background of being, in the eyes of the Jews, something less than Jew, was not an ideal choice.
According to Josephus, Herod had not come to Rome with the intent of being made king, but to propose that Aristobulus III, his wife’s brother, be made king. It is true that Aristobulus III had a better claim to the throne, being a member of the existing royal family. This fit squarely with Rome’s existing policy of naming kings form the existing royal family. But he was only 14 or 15 years old. Had Herod thought he would be regent until Aristobulus III came of age? Perhaps. In any event, Rome needed someone who would act now to defeat the Parthians. Who better than this Herod who had braved the mid-winter storms to come to Rome?
As mentioned before, Herod was appointed King within seven days of his arrival in Rome. Now, he quickly and decisively, left Rome to return to Judea.
Thus, while 40 BC had begun badly, it ended better for Herod for he was now King of Judea and Idumaea. But as King he now faced a myriad of problems: first, he had to oust Antigonius from his throne; second, Parthia was in control in Judea; third, the leading citizens of Jerusalem opposed him; fourth, some of his nearest kinsman, such as Lysanias of Chalcis, were allied with Antigonius; fifth, his credibility with his wife, her brother, and Hyrcanus must have greatly suffered when he returned as King and Aristobulus III was not; and sixth, his kingdom having been plundered by the Parthians, needed rebuilding.