Antipater (/ænˈtɪpətər/; Greek: Ἀντίπατρος Antipatros; c. 397 BC – 319 BC) was a Macedonian general and statesman under kings Philip II of Macedon and Alexander the Great, and father of King Cassander. In 320 BC, he became regent of all of Alexander the Great's Empire.
Nothing is known of his early career until 342 BC, when he was appointed by Philip to govern Macedon as his regent while the former left for three years of hard and successful campaigning against Thracian and Scythian tribes, which extended Macedonian rule as far as the Hellespont. In 342 BC, when the Athenians tried to assume control of the Euboean towns and expel the pro-Macedonian rulers, he sent Macedonian troops to stop them. In the autumn of the same year, Antipater went to Delphi, as Philip's representative in the Amphictyonic League, a religious organization to which Macedon had been admitted in 346 BC.
After the triumphal Macedonian victory at the Battle of Chaeronea in 338 BC, Antipater was sent as ambassador to Athens (337–336 BC) to negotiate a peace treaty and return the bones of the Athenians who had fallen in the battle.
He started as a great friend to both the young Alexander and the boy's mother, Olympias; there were even rumours that he was Alexander's father. He aided Alexander in the struggle to secure his succession after Philip's death, in 336 BC.