October 1, 332 BC
Battle of Gaugamela
The Battle of Gaugamela was a decisive military engagement fought on October 1, 331 BCE, where Alexander the Great's 47,000 Macedonian troops defeated Darius III's Persian army of 250,000 soldiers near modern-day Erbil, Iraq. This historic victory led to the collapse of the Persian Empire and established Macedonian dominance across Asia.