The Battle of Ipsus

Demetrius passed into Greece to fight Cassander. The other kings allied against him. At Ipsus in Asia Minor, twenty years after Alexander's death, the generals fought. Seleucus brought war elephants. Antigonus was killed; Demetrius fled to Ephesus. The fickle Athenians, who had worshipped him, now declared him an enemy and made speaking well of him punishable by death. The empire was divided into four parts: Ptolemy kept Egypt (his line ruled until Cleopatra); Seleucus had Persia/Syria with capitals at Seleucia and later Antioch; Lysimachus got Thrace; Cassander kept Macedon. Demetrius, having lost one kingdom, would conquer another.