Aristobulus was the younger son of Alexander Jannaeus, King and High Priest, and Alexandra Salome. After the death of Alexander in 76 BC, his widow succeeded to the rule of Judea and installed her elder son Hyrcanus II as High Priest. When Salome died in 67 BC, Hyrcanus succeeded to the kingship as well.
Aristobulus shared his late father's views on religion and politics. He entertained designs upon the throne, even during the life of his mother. He courted the nobles and military party by constituting himself the patron of the Sadducees and bringing their cause before the queen. The many fortresses which the queen placed at the disposal of the Sadducees, ostensibly for their defense against the Pharisees, constituted in reality one of the preparatory moves of Aristobulus for the usurpation of the government. The queen sought to direct his military zeal outside Judea, and sent him (70-69) against Ptolemy Mennæi; but when the undertaking failed, Aristobulus resumed his political intrigues. He left Jerusalem secretly and betook himself to his friends, who controlled the largest number of fortified places, with the intention of making war against his aged mother. But the queen died at the critical moment, and he immediately turned his weapons against his brother Hyrcanus, the legitimate heir to the throne.
Hyrcanus shared his mother's religious views, sympathetic to the Pharisees. In contrast to this, Alexander Jannaeus had the supported of the Saducees. Aristobulus agreed with his father's Sadducean stance and rebelled against his elder brother. Hyrcanus advanced against him at the head of his mercenaries and his followers. The brothers met in battle near Jericho and many of Hyrcanus' soldiers went over to Aristobulus, and thereby gave the latter the victory.
Hyrcanus took refuge in the citadel of Jerusalem; but the capture of the Temple by Aristobulus compelled Hyrcanus to surrender. A peace was then concluded, according to the terms of which Hyrcanus was to renounce the throne and the office of high priest, but was to enjoy the revenues of the latter office.
This agreement however did not last, as Antipater convinced Hyrcanus that Aristobulus was planning his death and to take refuge with Aretas III, King of the Nabataeans. The Nabataeans advanced toward Jerusalem with an army of 50,000 and besieged the city for several months.
As the Hasmoneans were allies of the Romans, both brothers appealed to Scaurus, each endeavoring by gifts and promises to win him over to his side. Scaurus, moved by a gift of 400 talents, decided in favor of Aristobulus and ordered Aretas to withdraw his army. During his retreat, the Nabateans suffered a crushing defeat at the hands of Aristobulus.
When Pompey arrived in Syria in 63 BC, both brothers and a third party that desired the removal of the entire dynasty, sent their delegates to Pompey, who however delayed the decision. He favoured Hyrcanus II over Aristobulus II, deeming the elder, weaker brother a more reliable ally of the Roman Empire.
Aristobulus and his sons Alexander and Antigonus were captured in 63 BC. Marc Antony had been commander of the cavalry under Gabinius, consul of the Roman province of Syria. Marc Antony was the man who scaled Aristobulus' fortification and subdued his forces with several men. This is the point that Aristobulus II and his son were taken prisoner. However, Aristobulus II escaped in 57 BC 
Aristobulos, suspicious of Pompey, entrenched himself in the fortress of Alexandrium, but when the Romans summoned their army, he surrendered and undertook to deliver Jerusalem over to them. However, since many of his followers were unwilling to open the gates, the Romans besieged and captured the city by force, badly damaging city and temple. Hyrcanus was restored as High Priest, but deprived of political authority.
Aristobulus was on his way to Judaea with his son Alexander, in 49 BC when "he was taken off by poison given him by those of Pompey's party". His son Alexander was beheaded by the Roman commander Scipio at Antioch.
Aristobulus IIDied: 37 BC
|King of Judaea
66 BC – 63 BC
|High Priest of Judaea
66 BC – 63 BC