Demetrius in Harpers Dictionary of Classical Antiquities

A Syrian, called Soter (Σωτήρ), or "the Preserver," the son of Seleucus Philopator, and sent by his father, at the age of twenty-three, as a hostage to Rome. He was living there in this condition when his father died of poison, B.C. 176. His uncle Antiochus Epiphanes thereupon usurped the throne, and was succeeded by Antiochus Eupator. Demetrius, meanwhile, having in vain endeavoured to interest the Senate in his behalf, secretly escaped from Rome, through the advice of Polybius the historian, and, finding a party in Syria ready to support his claims, defeated and put to death Eupator, and ascended the throne. He was subsequently acknowledged as king by the Romans. After this, he freed the Babylonians from the tyranny of Timarchus and Heraclides, and was honoured for this service with the title of Soter. At a subsequent period he sent his generals Nicanor and Bacchides into Iudaea, at the solicitation of Alcimus, the high-priest, who had usurped that office with the aid of Eupator. These two commanders ravaged the country, and Bacchides defeated and slew the celebrated Judas Maccabaeus. Demetrius at last became so hated by his own subjects, and an object of so much dislike, if not of fear, to the neighbouring princes, that they advocated the claims of Alexander Balas, and he fell in battle against this competitor for the crown after having reigned twelve years (from B.C. 162 to B.C. 150). His death was avenged, however, by his son and successor Demetrius Nicator (Just.xxxiv. 3Just., xxxv. 1).