Alexander the Great , also known as Alexander III and Alexander the Macedonian, was an ancient Greek king of Macedon . He was one of the most successful military commanders in history, and was undefeated in battle. By the time of his death, he had conquered most of the world known to the ancient Greeks.

Alexander assumed the kingship of Macedon following the death of his father Philip II of Macedon. Philip had united most of the city-states of mainland Greece under Macedonian rule . After reconfirming Macedonian hegemony by quashing a rebellion of southern Greek city-states, and staging a short but bloody excursion against Macedon's northern neighbors, Alexander set out east against the Achaemenid Persian Empire, which he defeated and overthrew. His conquests including Anatolia, Syria, Phoenicia, Judea, Gaza, Egypt, Bactria, and Mesopotamia, and extended the boundaries of his own empire as far as Punjab, India.