Battle of Thermopylae (279 BC)
The Battle of Thermopylae was fought in 279 BC between invading Gallic armies and a combined army of Greek Aetolians, Boeotians, Athenians, and Phocians at Thermopylae. The Gauls under Brennus were victorious, and advanced further into the Greek peninsula where they attempted to sack Delphi but were completely defeated.