Alexander assumed the kingship of Macedon following the death of his father Philip II, who had unified most of the city-states of mainland Greece under Macedonian hegemony in a federation called the League of Corinth. After reconfirming Macedonian rule by quashing a rebellion of southern Greek city-states and staging a short but bloody excursion against Macedon's northern neighbours, Alexander set out east against the Achaemenid Persian Empire, which he defeated and overthrew. His conquests included Anatolia, the Levant, Egypt, Bactria and Mesopotamia, and he extended the boundaries of his own empire as far as Punjab, India.
Alexander had already made plans prior to his death for military and mercantile expansions into the Arabian peninsula, after which he was to turn his armies to the west (Carthage, Rome and the Iberian Peninsula). His original vision, however, had been to the east, to the ends of the world and the Great Outer Sea, as described by his boyhood tutor and mentor Aristotle.
Alexander integrated many foreigners into his army, leading some scholars to credit him with a "policy of fusion". He also encouraged marriages between his soldiers and foreigners, and he himself went on to marry two foreign princesses.
Alexander died after twelve years of constant military campaigning, possibly a result of malaria, poisoning, typhoid fever, viral encephalitis or the consequences of alcoholism. His legacy and conquests lived on long after him and ushered in centuries of Greek settlement and cultural influence over distant areas. This period is known as the Hellenistic period, which featured a combination of Greek, Middle Eastern and Indian culture. Alexander himself featured prominently in the history and myth of both Greek and non-Greek cultures. His exploits inspired a literary tradition in which he appeared as a legendary hero in the tradition of Achilles.