In 480 BC, the Persian king Xerxes sends his massive army to conquer Greece. The Greek city of Sparta houses its finest warriors, and 300 of these soldiers are chosen to meet the Persians at Thermopylae, engaging the soldiers in a narrow canyon where they cannot take full advantage of their numbers. The battle is a suicide mission, meant to buy time for the rest of the Greek forces to prepare for the invasion. However, that doesn't stop the Spartans from throwing their hearts into the fray, determined to take as many Persians as possible with them