DEMETRIUS II., king of Macedonia, son of Antigonus Gonnatas, who was a son of Demetrius Poliorcetes. He occupied the throne for ten years, but little is known of him. His reign coincided with the period of the Achaean league, which was then strengthened by an alliance with the Oetolians. Only a fragment of Macedonian power remained in Greece; a few towns in the Peloponnesus were held by Macedonian governors. Demetrius offered a slight opposition to the two patriotic leagues, and wrested Baeotia from the Oetolians. At his death in 232 b.c. Antigonus Doson undertook the government for his son Philip, who was under age.

DEMETRIUS II., surnamed Nicator, the son of the preceding, lived in exile during the usurpation of Balas. At the head of a body of Cretan mercenaries, and with the assistance of Ptolemy Philometor, whose daughter he married, he regained the throne of Syria. His cruelties and vices, however, ultimately procured his expulsion from the kingdom; and Antiochus, the infant son of Balas, was proclaimed king in his stead. After ten years’ captivity in Parthia he succeeded in establishing himself once more upon the throne; but his wife Cleopatra, indignant at his subsequent marriage with a daughter of the Parthian king, procured his assassination (126 b.c.).

DEMETRIUS III., called Eucerus, also Euergetes and Philometor, king of Syria, was the fourth son of Antiochus Grypus. By the assistance of Ptolemy Lathyrus he recovered part of his Syrian dominions from Antiochus Eusebes, and held his court at Damascus. He assisted the Jews against Alexander Jannaeus. In attempting to dethrone his brother Philip he was defeated by the Arabs and Parthians and taken prisoner. He was kept in confinement in Parthia by king Mithridates until his death.