Thebes was the largest city of the ancient region of Boeotia and was the leader of the Boeotian confederacy. It was a major rival of ancient Athens, and sided with the Persians during the 480 BC invasion under Xerxes. Theban forces under the command of Epaminondas ended the power of Sparta at the Battle of Leuctra in 371 BC. The Sacred Band of Thebes (an elite military unit) famously fell at the Battle of Chaeronea in 338 BC against Philip II and Alexander the Great. Prior to its destruction by Alexander in 335 BC, Thebes was a major force in Greek history, and was the most dominant city-state at the time of the Macedonian conquest of Greece. During the Byzantine period, the city was famous for its silks.