Pyrrhus of Epirus
Antigonus father, Demetrius Poliorcetes, had been driven from the Macedonian throne by Pyrrhus of Epirus and Lysimachus in 288 BC. Tired of war, Demetrius surrendered himself to Seleucus I Nicator in 285 BC, leaving Antigonus as the Antigonid heir to the Macedonian throne.