The Spartans and their allies held off the Persian army for two days before being betrayed by Ephialtes on the third. By making the Persians aware of the existence of a goat path and then leading them through it, this action resulted in the encirclement of the remaining Greek force. If not for this, the Spartans and their fellow hoplites most likely would have been able to repel the invaders until reeinforcements arrived.
