Wars of the Diadochi

When Alexander the Great died at Babylon in June 323 BCE, he left a vast empire and no adult heir able to rule it. For the next half-century his leading generals and their sons, known as the Diadochi or "successors", fought one another for his inheritance. By about 272 BCE the empire had broken into three great monarchies, centred on Egypt, Asia and Macedon, which shaped the eastern Mediterranean world for the next two centuries.

The royal family offered only Alexander's half-brother Arrhidaeus, who was considered unfit to rule, and the child his wife Roxana was expecting. A compromise made them joint kings, as Philip III and Alexander IV, with the cavalry commander Perdiccas as regent. The generals divided the provinces among themselves: Ptolemy took Egypt, Antigonus the One-Eyed much of western Asia Minor, Lysimachus Thrace, while Antipater and Craterus held Macedon and Greece. At the same time the Greek cities, led by Athens, rose in the Lamian War and were defeated in 322 BCE.

Perdiccas's ambitions soon united the others against him. Ptolemy intercepted Alexander's body on its way to Macedon and joined the coalition, and when Perdiccas marched on Egypt and failed to force a crossing of the Nile, his own officers, among them Seleucus, murdered him. At Triparadisus Antipater became regent and Antigonus was given command in Asia.

A second war broke out in 318 BCE, setting Polyperchon, the new regent, against Cassander, who was backed by Antigonus. Polyperchon allied with Alexander's mother Olympias and invaded Macedon; Philip III was put to death, reportedly at her urging, before Cassander won the kingdom back and Olympias herself was killed. In Asia, Antigonus fought two indecisive battles against Alexander's former secretary Eumenes in the eastern provinces, then bribed Eumenes's veteran Silver Shields to hand their general over, and had him executed. Antigonus was now the strongest of the successors.

His rivals combined against him. In 312 BCE Ptolemy and Seleucus defeated Antigonus's son Demetrius at Gaza, and Seleucus returned to Babylon and built his own power in the east, holding it against Antigonus in the Babylonian War. Around 310 BCE Cassander had the boy-king Alexander IV and his mother killed, ending Alexander's dynasty. After Demetrius won a great sea battle off Cyprus in 306 BCE, Antigonus and his son took the title of king, and the other leading successors soon followed.

Demetrius went on to besiege Rhodes and to drive Cassander out of much of Greece. Facing defeat, Cassander, Lysimachus, Seleucus and Ptolemy allied again. In 301 BCE, at the Battle of Ipsus in Phrygia, Antigonus was killed and his Asian lands were shared out between the victors.

The struggle then turned to Macedon. Demetrius seized the throne in 294 BCE but was driven out a few years later and died a captive of Seleucus. In 281 BCE Seleucus defeated and killed Lysimachus at Corupedium, becoming the last survivor of Alexander's generals, only to be assassinated soon afterwards by Ptolemy Ceraunus, an exiled son of Ptolemy.

Lysimachus's death left Macedon's northern frontier open, and Gallic war-bands overran Macedon and Greece and crossed into Asia Minor, where some settled in the region later called Galatia. Demetrius's son Antigonus Gonatas defeated them and became king of Macedon in 277 BCE. His last serious rival, Pyrrhus of Epirus, was killed at Argos in 272 BCE.

By then three dynasties had emerged: the Ptolemies in Egypt, the Seleucids in Asia and the Antigonids in Macedon and much of Greece. Their rivalries and wars filled the Hellenistic period that followed.

Our 323 BCE map shows the Macedonian Empire at Alexander's death, and our 300 BCE map shows the rival kingdoms that had replaced it just after Ipsus.