(331 BC) Clash between the forces of Alexander the Great and Darius III of Persia that brought the fall of the Persian empire.
Attempting to stop Alexander's incursions, Darius prepared a battleground on the Plain of Gaugamela in present-day Iraq and, with his much larger army, waited for Alexander. His plans were undone by Alexander's brilliant tactics; when Darius saw defeat was imminent, he fled and his army was cut down. Alexander's victory gave him control of South Asia.