  In 343, upon the request of Philip, the king of Macedon, Aristotle left Lesbos for Pella, the Macedonian capital, in order to tutor the king’s thirteen-year-old son, Alexander—the boy who was eventually to become Alexander the Great. Although speculation concerning Aristotle’s influence upon the developing Alexander has proven irresistible to historians, in fact little concrete is known about their interaction. On the balance, it seems reasonable to conclude that some tuition took place, but that it lasted only two or three years, when Alexander was aged from thirteen to fifteen. By fifteen, Alexander was apparently already serving as a deputy military commander for his father, a circumstance undermining, if inconclusively, the judgment of those historians who conjecture a longer period of tuition. Be that as it may, some suppose that their association lasted as long as eight years.