Alexander of Macedon set off to conquer the Persian Empire with 40,000 men in 334 BC. He defeated the Persian forces along the Ionian coast and in Egypt before completely defeating Darius III with a smaller army at the Battle of Gaugamela on October 1, 331 BC.
Alexander created one of the largest empires in the world and his conquests left a lasting legacy from the Ionian Sea to the Himalayas. He is considered one of history’s greatest military commanders.