It was the largest city of the region of Boeotia and was the leader of the Boeotian confederacy. It was a major rival of Athens, and sided with the Persians during the 480 BCE invasion of Xerxes. Theban forces under the command of Epaminondas ended the power of Sparta at the battle of Leuctra in 371 BCE. The Sacred Band of Thebes (an elite military unit) famously fell at the battle of Chaeronea in 338 BCE against Philip II and Alexander the Great.