Who was Alexander the Greats mentor?
Aristotle.
When Alexander was thirteen, Philip, to this point not much involved in his son’s upbringing, decided to choose a tutor for him. The result would become one of the most famous mentors-student relationships in history.
Alexander’s education took place in a setting removed from the capital city of Pella, in the more isolated village of Mieza, within the so-called Precinct of the Nymphs. In this rural seclusion, Alexander was joined by several of his most notable peers, some of them future kings themselves.
Though perhaps best known for his scientific treatises, Aristotle also published his Ethics and Politics, and his influence in these areas also reached Alexander. Aristotle asserted this influence particularly with regard to the so-called barbarians–a term that was used to characterize essentially all non-Greeks. Alexander himself was already passionately anti-Persian; and Aristotle provided him with the intellectual justifications for his fated and inherited mission. Aristotle believed that slavery was a natural institution, and that barbarians were by nature meant to be slaves. He therefore encouraged Alexander to be a leader to Greeks and a despot to barbarians, treating the former as friends and the latter as beasts.