Thermopylae and King Leonidas of Sparta are linked together by the battle that took place here in 480 BC. The heavily outnumbered Greek forces led by Leonidas held the critical pass for three days against the much larger Persian army led by Xerxes. The Greeks were finally outflanked after they were betrayed by a local named Ephialtes. Leonidas realized the inevitable and dismissed the bulk of the Greek army and remained with 300 Spartans, 700 Thespians and 400 Thebans. Most were killed. Thermopylae has become a symbol of courage against overwhelming odds.