How and why did Alexander the Great create an empire?

AAlexander (r. 336–323 B.C.E.) carried out his father Philip’s plan to lead the Greeks against the Persians. His campaign swept away the Persian Empire, which had ruled the area for over two hundred years. In its place Alexander established a Macedonian monarchy. Although his rule over these vast territories was never consolidated due to his premature death, he left behind a legacy of political and cultural influence, and a long period of war. Macedonian kings established dynasties and Greek culture spread in this Hellenistic era.

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Alexander at the Battle of IssusIn this first-century-B.C.E. mosaic from the Roman city of Pompeii, Alexander the Great (left), bareheaded and wearing a breastplate, charges King Darius III (right), who is standing in a chariot. Alexander was widely admired by Romans, and this mosaic portrays him in a heroic light, just at the point in the battle when Darius turns to flee from the attack. (C. M. Dixon/Ancient Art & Architecture Collection Ltd.)