In 480 BC, 300 Spartans made a famous stand at Thermopylae, as hordes of Persian soldiers, led by Xerxes, seemed set to succeed in their aim of conquering Greece. However, although Leonidas and his men were defeated, only a short while later the Greek navy, against superior Persian forces, routed them in the Straits of Salamis, a turning point in the war as the Persians were steadily swept out of Greece. Tom Holland and Dominic Sandbrook discuss the epic battle and its outcome.