The Battle of Lysimachia was fought in 277 BC between the Gallic tribes settled in Thrace and a Greek army of Antigonus at Lysimachia, Thracian Chersonese. After the Greek defeat at Battle of Thermopylae, the Gauls retreated out of Greece and moved through Thrace and finally into Asia.
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.