Demetrius II (Demetrius Nicator) (dĬmē´trēəs nīkā´tər), d. c.125 BC, king of ancient Syria, son of Demetrius I. He was aided against the usurper, Alexander Balas, by Ptolemy VI (Ptolemy Philometer). He married Ptolemy's daughter, Cleopatra Thea, even though she was already married to Alexander Balas. Demetrius ascended the throne in 146 BC, but in fighting against the Parthians in 141 he was captured. Before his capture Demetrius reaffirmed Judaean independence, freeing the Jews from Syrian taxation. Tryphon, who served under Alexander Balas as governor of Antioch, had revolted and had put Alexander Balas' infant son, Antiochus Dionysius, on the throne. Two years later Tryphon murdered the boy and took the throne himself. Demetrius, coming back from prison, regained the throne in 128 BC He soon lost it again and died in battle at Tyre, fighting a war with Egypt.

Demetrius II, d. 229 BC, king of Macedon (239–229 BC), son of Antigonus II. His reign was a confusion of wars and invasions, mostly concerned with possession of Epirus. The Aetolian League and the Achaean League united against him and defeated him. His heir was his son Philip V.