3. Simon immediately declared for Demetrius, and was confirmed by the latter in the high-priesthood.
He was the most fortunate of the heroic sons of Mattathias. IIe renewed the alliance with the Romans, fortified many towns, and expelled eventually the Syrian garrison from the fortress in Jerusalem. Under his fostering care the country began to recover from the ravages of the long protracted wars, and gradually increased in wealth and prosperity. Still he was not destined to end his days in peace. In B. C. 137, Antiochus VII., who had succeeded his brother Demetrius Nicator, unwilling to lose Judaea, which had now become an independent state, sent an army, under his general Cenbedeus, to invade the country.
The aged Simon entrusted the conduct of the war to his sons Judas and Joannes Hyrcanus, who conquered Cenbedeus, and drove him out of the country. But Simon did not long enjoy the fruits of his victory. His son-in-law Ptolemy, the governor of Jericho, instigated by Antiocius, formed a plot to obtain the government of Judaea.
He treacherously seized Simon at a banquet, and put him to death with two of his sons, Judas and Mattathias, B. C. 135. His other son Joannes Hyrcanus escaped, and succeeded his father.