The true story behind the events in 300: Rise of an Empire, the sequel to Zack Snyder's 300. The action-filled movie 300 focused on Ancient Greece's epic battle of Thermopylae, in which King Leonidas led 300 Spartans into battle against Xerxes and his million-strong Persian forces. In the sequel, 300: Rise of an Empire, the action moves to the sea, covering ten years starting with the Battle of Marathon and ending with naval engagement the Battle...

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