Ten years later, a second invasion was launched by Darius' son Xerxes. The city-states of northern and central Greece submitted to the Persian forces without resistance, but a coalition of 31 Greek city states, including Athens and Sparta, determined to resist the Persian invaders. At the same time, Greek Sicily was invaded by a Carthaginian force. In 480 BC, the first major battle of the invasion was fought at Thermopylae, where a small rearguard of Greeks, led by three hundred Spartans, held a crucial pass guarding the heart of Greece for several days; at the same time Gelon, tyrant of Syracuse, defeated the Carthaginian invasion at the Battle of Himera.