Greek general Themistokles attempts to unite all of Greece by leading the charge that will change the course of the war. Themistokles faces the massive invading Persian forces led by mortal-turned-god, Xerxes and Artemesia, the vengeful commander of the Persian navy.

King Leonidas of Sparta and a force of 300 men fight the Persians at Thermopylae in 480 B.C.