A disloyal high priest during the time between the Old and New Testaments in Jewish history. He came from Aaron's family but was not from the proper high priest line. Around 163 BC, the Syrian king Demetrius I made Alcimus the high priest.
Alcimus favored Greek culture, which upset the Maccabeans who controlled Jerusalem. They did not want him as high priest. So Alcimus asked King Demetrius to send General Bacchides to control Judah.
Bacchides put Alcimus in charge, but Judas Maccabeus and his brothers fought against those who supported Alcimus (1 Maccabees 7:1–24). Alcimus asked for help again. Demetrius sent an army led by Nicanor, but the Maccabeans defeated them (1 Maccabees 7:25–50).
Then Demetrius sent Bacchides back with a stronger army. This time, Judas Maccabeus was killed, and Alcimus took control of Jerusalem (1 Maccabees 9:1–53). He "gave orders to tear down the wall of the inner court of the sanctuary," but before he could finish, he became paralyzed. "Alcimus died at that time in great agony" around 161 BC (1 Maccabees 9:54–57).