In 480 B.C., the forces of the Persian Empire under King Xerxes numbered—according to the ancient Greek historian Herodotus—two million men. The Persian army bridged the Hellespont and marched to invade Greece. King Leonidas of Sparta and 300 handpicked Spartan warriors—along with Hoplites from another Greek city-state—marched to meet Xerxes at the narrow mountain gap along the coast at Thermopylae. The gap along the coast was a mere 60 feet wide and was the best location for a blocking action.