Alexandra joined herself to the Pharisees, a sect among the Jews most strict in the observance of the laws, and who had been opposed to her husband. These Pharisees so won the queen's favor that they became the real rulers of the nation, which, as Alexandra managed affairs with great sagacity, had become very great and powerful.

The Pharisees were desirous of revenging themselves for what they had suffered at the hands of the late king and his party. So they put to death Diogenes, a friend of Alexander’s because they charged him with having advised the king to crucify the eight hundred men. And they demanded that Alexandra should put to death all who had aided the execution. Many were slain, but many who were in danger fled to Aristobulus, the younger son, and sought his intercession. He persuaded his mother to spare them, but they were obliged to leave Jerusalem and disperse themselves about the country.

Alexandra sent an army to Damascus, and under pretence that Ptolemy was always oppressing the city she captured it. Soon after this she fell ill. The young and ambitious Aristobulus seized this opportunity to gain the throne. He fled from Jerusalem, got possession of the fortresses, hired a number of troops, and made himself king. Alexandra in the mean while died, after a prosperous reign of nine years, leaving the kingdom to Hyrcanus, the rightful heir.

Aristobulus advanced upon his brother, who met him with an army near Jericho. But before a battle was fought the greater part of Hyrcanus’s army deserted to Aristobulus. The rest fled, Hyrcanus with them, to a place called the Citadel, where the party of Hyrcanus had shut up the wife and children of Aristobulus as hostages. It was finally agreed between the two brothers that Aristobulus should ascend the throne, and that Hyrcanus should possess such dignities as became the brother of the king.

This state of affairs did not, however, last long. Antipater, an Idumean by birth, and a very wily man, who possessed much influence over the weak Hyrcanus, persuaded him to fly to Aretas, the king of Arabia. Aretas, having been well disposed to help the cause of Hyrcanus by the presents and eloquence of Antipater, marched an army of fifty thousand horse and foot against Aristobulus, who was deserted at the first onset by many of his army, and driven to Jerusalem, where he soon would have been captured but for timely assistance.

Scaurus, a lieutenant of Pompey the Great, had seized Damascus. Both brothers sought his aid. Aristobulus, however, sent a present of three hundred talents, which won Scaurus to his side, and Aretas was threatened with the vengeance of Rome unless he raised the siege. So the Arabian was frightened, and withdrew his forces, followed by Aristobulus, who fell upon the retreating army from the rear and completely routed it.

Hyrcanus and Antipater, being thus deprived of their hopes from the Arabians, now looked for aid from Pompey, who had come himself to Damascus, and besought him to bestow the throne of Judea upon the rightful heir. Aristobulus also sought Pompey’s assistance, relying upon the presents he had formerly given to Scaurus. But Aristobulus behaved in so haughty a manner that he displeased Pompey, so he gathered together his forces and besieged Aristobulus in the strong fortress of Alexandrium. Aristobulus, frightened by Pompey’s large army, tried to make peace, and came down from his fortress to parley with Pompey. Pompey forced him to sign orders for the surrender of all his fortresses. This was too much for the high spirit of Aristobulus. He fled to Jerusalem and prepared to resist the Roman general.

Pompey immediately advanced upon Jerusalem. Aristobulus, who found the city divided within itself, became alarmed, and, coming out to Pompey, promised to surrender himself and the city, and to pay a large sum of money. But when Pompey sent Gabinius to collect the money, the soldiers of Aristobulus would not allow him to enter the gates.