•King Leonidas, King of Sparta.
•Queen Gorgo, Queen of Sparta
•Pleistarchus, son of Leonidas and Gorgo
•Theron, a fictional corrupt Spartan politician
•Dilios, narrator and Spartan soldier.
•Captain Artemis, Leonidas' loyal captain and friend.
•Astinos, Captain Artemis' eldest son.
•Daxos, an Arcadian leader who joins forces with Leonidas. •Ephialtes, a deformed Spartan outcast and traitor.
•King Xerxes, God-King of Persia
•The Loyalist, a loyal Spartan politician.
•Stelios, a young, spirited and highly skilled Spartan soldier. •Persian messenger who tries to get Sparta to submit.
•Pythia, an Oracle to the Ephors.
•Tyler Neitzel as young Leonidas.
•Uber Immortal (giant), a muscular and deranged Immortal who battles Leonidas during the Immortal fight. •Persian General who tries to get Leonidas to comply at the end of the battle. •Executioner, a hulking, clawed man who executes men with whom Xerxes is displeased.
Dilios, a Spartan soldier, narrates the story of Leonidas from his boyhood to becoming a king of Sparta. Years later, a Persian messenger arrives at the gates of Sparta, demanding the submission of Sparta to King Xerxes. In response to this demand, Leonidas kicks the messenger into a large well. Knowing this will prompt a Persian attack, Leonidas visits the Ephors—ancient leprosy-ridden priests whose blessing he needs before the Spartan council will authorize going to war. He proposes they repel the numerically superior Persians by using the terrain of Thermopylae (the Hot Gates) and funneling the Persians into a narrow pass between the rocks and the sea. The Ephors consult the Oracle, who decrees that Sparta must not go to war during their religious festival Carnea. As Leonidas departs, two agents of Xerxes appear—one of them, Theron, a Spartan—who bribe the Ephors with concubines and money. Leonidas follows his plan anyway, setting out with only 300 soldiers, whom he calls his personal guards to avoid...