Much of the adult Alexander's character can be ascribed to the formative influence of his parents. Alexander's mother, Olympias, greatly influenced Alexander and, remarkably, given that women in ancient Greece usually lacked political power, the affairs of their country as well. Born a princess of Epirus, Olympias was a willful young woman when she came to Macedon to become Philip's primary wife. After years of an increasingly discordant marriage, Philip married Cleopatra, a young woman of pure Macedonian blood. This so angered Olympias that she returned to Epirus, taking the teen-age Alexander with her. Apparently a force to be reckoned with throughout her son's life, Olympias contributed to Alexander her prideful self-possession and strong will and fostered his sense of his destiny, while also helping to estrange him from his father.

His father's own notable achievements both helped and hindered Alexander.

Philip's creation of...