Antigonus I Monophthalmus at English => English (The Britannica Concise) Of Explained:
Founder of the Macedonian dynasty of the Antigonids. He served as a general under Alexander the Great. From the plots, alliances, and wars among Alexander's successors, he emerged in control of Asia Minor and Syria, though he soon relinquished the lands east of the Euphrates to Seleucus I Nicator. In 307 his son Demetrius I ousted the governor of Athens and conquered Cyprus, giving Antigonus control of the E Mediterranean, the Aegean, and Asia Minor. In 306 he was proclaimed king of the empire by the assembled army. In 302 he and his son renewed the Panhellenic League (consisting of all the Hellenic states except Sparta, Messenia, and Thessaly), in order to ensure peace in Hellas and protect Antigonus. His dreams of taking Macedonia itself and Alexander's entire former empire died with him at the Battle of Ipsus (301), the only battle he ever lost.