King of Syria; son of Antiochus Grypus. He was pretender to the throne of Antiochus X., whom he supplanted in 95 B.C. after a severe struggle. He divided the authority with his brother Philip, keeping to himself apparently Cœle-Syria. In the year 88 the Jews appealed to him for aid against their king, Alexander Jannæus, who was subsequently defeated. But thousands of Jews renewed their allegiance to their defeated king, probably out of a well-founded apprehension that Demetrius would again subject them to the Syrian rule. Demetrius was taken prisoner in a battle against his brother Philip, and died in captivity.