Xerxes looked on while his soldiers fought at the entrance to the pass. And they did their best, for they were unwilling that their king should see them beaten back by men who had spent their days in games or in bedecking their hair. But they could not stand against the fierce attacks of the Spartans, and at length, when many of their number had been slain, they withdrew. The king then ordered his own chosen bodyguard, the ten thousand famous Immortals, to advance against the gallant defenders of the pass. Even at the approach of these renowned warriors, the Spartans did not waver. They pretended to flee, only to turn and slay the barbarians who had followed them into the pass. At length after a furious conflict, the Immortals were forced to give way and return to their camp. Three times as he watched his Immortals, Xerxes sprang from his throne, thinking that all was lost. But the next day he sent them against the foe once more, for now he believed that the Spartans would be too weary to fight. But Leonidas was careful of the little band he commanded. It was easy to hold the pass with only a small number of men. As each company grew tired, the king ordered it to withdraw and sent a fresh one to take its place. Soon the entrance to the pass was choked with the dead bodies of the barbarians. Some of the most valiant of Xerxes’ warriors were next sent against the enemy. But they were cowed by the bravery of the Spartans, and as they saw their comrades falling around them, they turned to flee. Then their officers drove them back with lashes. For two days, the terrible slaughter never ceased, and Xerxes was almost ready to leave the pass to its brave defenders, so hopeless seemed the task of taking it. But that night, a Greek named Ephialtes came to the great king, and for a large sum of money, he offered to show the Persians a path which led over the hill down to the pass of Thermopylae. The path was the tiny track that was guarded by the Phocians. The offer of the traitor was at once accepted, and at midnight Xerxes sent his officer Hydarmes, at the head of his Immortals, to follow Ephialtes. ‘All night long they followed the path with the mountains on the right and on the left. The day was dawning when they reached the peak of the mountain, and there the thousand Phocians were keeping watch and guarding the pathway. While the Persians were climbing the hill, the Phocians knew not of their coming, for the whole hill was covered with oak trees, but they knew what had happened when the Persians reached the summit. Not a breath of wind was stirring, and they heard the trampling of their feet as they trod on the fallen oak leaves.’