On the way, however, Alexander, the eldest son of the captive king, managed to effect his escape, and returned to Judæa, where, rallying round him the partisans of his father, he seized the fortresses of Alexandrium, Hyrcania, and Machærus, and began to attack the adherents of Hyrcanus. Alarmed at the progress of the invader, and unable to make head against him themselves, the ethnarch and Antipater called in the aid of the Romans, and Gabinius, who had been appointed prefect of Syria, B.C. 57, deputed Marcus Antonius, his master of the horse, to render the required assistance. Antonius, having defeated the invader in a short engagement, shut him up in the stronghold of Alexandrium, and on the arrival of Gabinius forced him, after a somewhat protracted siege, to purchase his life by the surrender of the three fortresses, which were now demolished[67]. Gabinius now employed himself in completely reorganizing the government of the country. Hitherto the nominal power had centred in Hyrcanus. Now he was deprived of even this semblance of authority, which was placed in the hands of the aristocracy, five independent senates or Sanhedrins being established, the first sitting at Jerusalem, the second at Jericho, the third at Gadara, the fourth at Amathus, the fifth at Sepphoris[67]. These arrangements made for destroying the influence of the capital as a centre of union, Gabinius returned to Syria. But scarcely had he done so, when Aristobulus himself reappeared, having escaped from Rome with his younger son, Antigonus. He was, however, more quickly disposed of even than Alexander had been, for the prefect of Syria instantly dispatched a force against him, and having overpowered his adherents, sent him back as a prisoner to Rome with his son, who was afterwards, however, released. Gabinius now proceeded with Antonius to Egypt to place Ptolemy Auletes upon the throne, and both generals were strenuously assisted by Hyrcanus and Antipater, who sent supplies for their armies, and urged the Jews at Leontopolis to befriend them in like manner. Taking advantage of the absence of the legions, Alexander made a second attempt to recover the supreme power, but only to be a second time defeated near Mount Tabor by the Roman commanders on their return from Egypt, with a loss of 10,000 men.