In 336 BC, King Philip was killed and Alexander ascended to the throne of Macedonia. Over the next twelve years Alexander conquered almost the entire known world of his era, irrevocably changing the course of history. In doing so he defeated the Thebans, the Persian Satraps, overthrew Darius, overran Syria and Phoenicia, possessed himself of all the cities along the Mediterranean, conquered Egypt and founded Alexandria.
He died suddenly at age 33, in Babylon, after a bout of heavy drinking; some suggest he was poisoned, though no cause of death has ever been proved.