(301 BC) Battle marking the defeat at Ipsus, Phrygia, of Antigonus I Monophthalmus and his son Demetrius I Poliorcetes at the hands of Lysimachus of Thrace, Seleucus I Nicator of Babylon, Ptolemy I Soter of Egypt, and Cassander of Macedonia.
Antigonus was killed and his Asian territory lost, but Demetrius kept territory in Greece and Macedonia. The battle was part of the struggle for control of territories that made up Alexander the Great 's empire.