The Battle of Thermopylae
The Battle of Thermopylae took place in 480 BC. The Spartans, who chose to send a token force of 300 men to defend the pass held out along with 4,900 men from allied cities against over a million Persians for a week before they were all killed. When Pheidippides tells Xena that at Marathon the Persians had shot so many arrows they blocked out the sun, this is a reference to an actual story from the Battle of Thermopylae. According to the historian Herodotus, when King Xerxes ordered the Spartan King Leonidas and his 300 Spartan companions to surrender, saying that his men would fill the sky with so many arrows that it would block out the sun, Leonidas told Xerxes, "Good, then we'll fight in the shade."