Alexander the Great Conquers the Persian Empire

Alexander III of Macedon crossed into Asia in 334 BCE and systematically dismantled the Persian Empire — Granicus, Issus, Gaugamela, each battle more decisive than the last. By 323 BCE he'd conquered everything from Egypt to India. He founded over 20 cities named Alexandria and spread Greek culture across the Near East so thoroughly that the region spoke Greek for centuries. He died at 32 in Babylon, possibly from fever, possibly from poison. His empire shattered immediately but the cultural impact was permanent.