(dīăd'Әkī) [Gr.,=successors], the Macedonian generals and administrators who succeeded Alexander the Great. Alexander's empire, the largest that the world had known to that time, was quickly built. At his death in 323 B.C. it disintegrated even more quickly. Alexander's more important followers, later known as the Diadochi, sought to increase their personal power in a bloody scramble. Chief among them were Antipater, Perdiccas, Eumenes, Craterus, Antigonus (Antigonus I), Ptolemy (Ptolemy I), Seleucus (Seleucus I), and Lysimachus.
The first struggle was over the regency; theoretically Alexander's feeble-minded brother, Philip, and also Alexander's posthumous son by Roxana had the real claim to the inheritance. Perdiccas had the regency (323–322), in effect if not in name, to which Antipater also had claim. Eumenes supported Perdiccas, while Antigonus, Ptolemy, and Craterus supported Antipater. In 321, battle was joined; the allies of Antipater won, although Craterus was killed. On the death (319) of Antipater the struggle was on again. There were shifting alliances, but in general the chief figure was Antigonus, who, with the help of his son, Demetrius Poliorcetes (Demetrius I of Macedon), attempted to rebuild Alexander's empire. He failed. Antigonus and Demetrius were finally defeated in the battle of Ipsus (301 B.C.). The Diadochi had been declaring themselves kings, Antigonus first and then the others.
The contest was carried on to the next generation, with Demetrius fighting successfully against Cassander, the son of Antipater, and it was pursued even further with the wars between the Seleucidae and the Ptolemies. Commonly, however, the period of the Diadochi is said to end with the victory of Seleucus I over Lysimachus at the battle of Corupedion in 281, fixing the boundaries of the Hellenistic world for the next century. This left the descendants of Ptolemy, Seleucus, and Antigonus as the chief claimants to power in the Hellenistic age, and the empire of Alexander was irrevocably split.