Thermopolae

n 480 BC, Leonidas went to Thermopylae with 300 of his personal guards, all with sons to carry on their names, where he was joined by forces from other Greek city-states, who put themselves under his command to form an army 7,000 strong. This force was assembled in an attempt to hold the pass of Thermopylae against hundreds of thousands of Persian soldiers who had invaded from the north of Greece under Xerxes I. Leonidas took only his personal guard, and not the army, because Spartan religious customs forbade sending an army at that time of year. In addition, the Oracle of Delphi had foretold that Sparta could be saved only by the death of one of its kings, one of the lineage of Heracles.


Leonidas and his men repulsed the Persians' frontal attacks for the first two days, killing roughly 20,000 of the enemy troops and losing very few of their own. The Persian elite unit known to the Greeks as "the Immortals" were held back, and two of Xerxes' brothers died in battle. On the third day, a Malian Greek traitor named Ephialtes led the Persian general Hydarnes by a mountain track to the rear of the Greeks. At that point Leonidas sent away all Greek troops and remained in the pass with his 300 Spartans, 900 Helots and 700 Thespians who refused to leave. Another 400 Thebans were kept with Leonidas as hostages. The Thespians stayed entirely of their own will, declaring that they would not abandon Leonidas and his followers. Their leader was Demophilos, son of Diadromes, and as Herodotus writes: "Hence they lived with the Spartans and died with them".



One theory provided by Herodotus is that Leonidas sent away the remainder of his men because he cared about their safety. The King would have thought it wise to preserve those Greek troops for future battles against the Persians, but he knew that the Spartans could never abandon their post on the battlefield. The soldiers who stayed behind were to protect their escape against the Persian cavalry. Herodotus himself believes that Leonidas gave the order because he perceived the allies to be out of heart and unwilling to encounter the danger to which his own mind was made up. He therefore chose to dismiss all troops except the Thespians and Helots and save the "glory" for the Spartans.