At the death of his father, the twenty-year-old Alexander became king. A natural warrior, he also received a formal education under the philosopher Aristotle. Alexander lived only thirteen years after his accession to the throne, but in that time he created the largest empire ever seen, and he had perhaps a greater impact on Western civilization than any other man of the ancient world. As with many great men, his life is shrouded in myth and legend.

In 334 B.C., after securing his base in Greece, Alexander invaded Asia Minor with 30,000 troops, quickly capturing the Turkish coastline to deprive the Persian fleet of its ports. Using brilliant tactics, he then defeated a much larger Persian army under Darius in a series of battles in northern Syria. Alexander then captured Egypt and Mesopotamia, defeating 100,000 Persians in a climactic battle at Guagamela in 331 B.C. Before dying of a malarial fever at age thirty-three, Alexander conquered Afghanistan and parts of India as well.

Alexander used both military and administrative skills to build his empire. He was able to integrate the various peoples he had conquered into a unified empire by devising appropriate forms of administration in each region. In Egypt he became the pharaoh. In Mesopotamia he became the great king. In Persia, however, he kept the indigenous administrative system intact under joint Persian and Macedonian rule. He founded hundreds of new settlements, encouraging his men to marry local women. And he manipulated the local religions to legitimize his own rule. In creating his empire, Alexander changed the face of the world.