Philip and his army joined his son in 338 BC, and they marched south through Thermopylae, taking it after stubborn resistance from its Theban garrison. They went on to occupy the city of Elatea, only a few days' march from both Athens and Thebes. The Athenians, led by Demosthenes, voted to seek alliance with Thebes against Macedonia. Both Athens and Philip sent embassies to win Thebes's favour, but Athens won the contest. Philip marched on Amphissa (ostensibly acting on the request of the Amphictyonic League), capturing the mercenaries sent there by Demosthenes and accepting the city's surrender. Philip then returned to Elatea, sending a final offer of peace to Athens and Thebes, who both rejected it.