In 356 B.C., Alexander III was born to Phillip II, king of Macedonia, and Olympia, the daughter of the late King Epirus. Though that family background seemed to suggest that he was destined for greatness, few would have predicted that he would become one of the most feared and adored conquerors in history. In this four-part documentary, historian Michael Wood traces the route of the 21-year-old Alexander and his Greek army as they set out to invade Asia and overthrow the Persian Empire.