Philip II of Macedon

Philip II became king of Macedon in 359 BC, inheriting a kingdom on the margins of Greek affairs. Over the next two decades, he transformed it through military reform - the Macedonian phalanx, combined arms, siege engines - and shrewd diplomacy and marriage alliances. In 338 BC he crushed Athens and Thebes at Chaeronea, then forged the Greek city-states into the Hellenic League with himself as hegemon and commander. He was planning an invasion of the Achaemenid Empire when Pausanias of Orestis, a royal bodyguard, assassinated him in October 336 BC. His son Alexander took the throne and carried out the Persian campaign in his place.