(Δημήτριος) I., king of SYRIA, surnamed SOTER (Σωτήρ), was the son of Seleucus IV. (Philopator) and grandson of
Antiochus the Great. While yet a child, he had been sent to Rome by his father as a hostage,
and remained there during the whole of the reign of Antiochus Epiphanes. He there formed an
intimacy with the historian Polybius. After the death of Antiochus, being now 23 years old, he
demanded of the senate to be set at liberty and allowed to occupy the throne of Syria in
preference to his cousin, Antiochus Eupator. His request however having been repeatedly
refused by the senate, he fled secretly from Rome, by the advice and with the connivance of
Polybius, and landed with a few followers at Tripolis in Phoenicia. The Syrians immediately
declared in his favour; and the boy Antiochus with his tutor Lysias were seized by their own
guards and put to death. (Plb. 31.12, 19-23; Appian, App. Syr.
46, 47; Justin, 34.3; Liv.
Epit. xlvi.; Euseb. Arm. p. 166, fol. edit.; 1 Macc. vii.; Zonar. 9.25.) As soon as he had established
himself in the kingdom, Demetrius immediately sought to conciliate the favour of the Romans by
sending them an embassy with valuable presents, and surrendering to them Leptines, who in the
preceding reign had assassinated the Roman envoy, Cn. Octavius. Having thus succeeded in
procuring his recognition as king, he appears to have thought that he might regulate at his
pleasure the affairs of the East, and expelled Heracleides from Babylon, where as satrap he
had made himself highly unpopular; for which service Demetrius first obtained from the
Babylonians the title of Soter (Plb. 32.4, 6; Diod. Exc. Leg. xxxi.; Appian, App. Syr. 47.) His
measures against the Jews quickly drove them to take up arms again under Judas Maccabaeus, who
defeated Nicanor, the general of Demetrius, and concluded an alliance with the Romans, by
which they declared the independence of Judaea, and forbade Demetrius to oppress them. (J. AJ 12.10; 1Macc. vii. viii.) He further incurred the enmity of the Romans by
expelling Ariarathes from Cappadocia, in order to substitute a creature of his own: the Roman
senate espoused the cause of Ariarathes, and immediately restored him. (Plb. 32.20; Appian, App. Syr. 47; Liv. Epit. xlvii.; Justin, 35.1.)
While Demetrius was thus surrounded on all sides by enemies, his own subjects
at Antioch were completely alienated from him by his luxury and intemperance. In this state of
things, Heracleides, whom he had expelled from Babylon, set up against him an impostor of the
name of Balas, who took the title of Alexander, and pretended to be the son of Antiochus
Epiphanes. This competitor appears to have been at first unsuccessful; but, having obtained
the powerful protection of Rome, he was supported also with large forces by Attalus, king of
Pergamus, Ariarathes, king of Cappadocia, and Ptolemy Philometor, as well as by the Jews under
Jonathan Maccabaeus. Demetrius met him in a pitched battle, in which he is said to have
displayed the utmost personal valour, but was ultimately defeated and slain. (Plb. 33.14, 16; Appian, App. Syr. 67; Diodor. Exc. Vales. xxxiii.; Justin, 35.1; J. AJ 13.2; 1Macc. x.; Euseb. Arm. p. 166.) Demetrius died in the year B. C. 150, having reigned between eleven and twelve years. (Clinton, F. H. iii. p. 323; Plb. 3.5.) He left two sons,
Demetrius, surnamed Nicator, and Antiochus, called Sidetes, both of whom subsequently ascended
the throne.