The allies, therefore, with the exception of the Thespians and the Thebans, departed, and the brave remainder prepared themselves for their death. Hitherto, Leonidas had stood on the defensive in order to spare the lives of his men, but now, knowing that death must come, he desired only to work as great havoc among the Persians as possible, and he therefore marched his men out before the wall and fell upon the vanguard of the Persian army. It does not seem strange that the hired soldiers should have feared to meet this little band of Greeks, and indeed it is told that the Persian captains were obliged to go behind their troops and with whips scourge them to the fight. Many of the Persians were forced into the sea and so died; some were trodden under foot, and thousands fell by the hands of the Greeks. But it was not only the Persians who fell in this fierce struggle; Leonidas was one of the first who was slain, and many other Spartans fell with him.
But the death of their leader did not demoralize the Greeks--it only made them more reckless and more desperate. At length they saw that the end was close at hand; the "Immortals," who had come in the night over the mountain, had arrived, and were ready to fall upon their rear. Closely pressed by the Persians, they drew back to the narrowest part of the pass, where they had fought on the preceding days, and there made their last stand. Their spears were broken, their swords were dulled; but even had their weapons been still of the best, it would have availed them little, for the Persians, all too well acquainted now with the Greek daring, refused to close with their enemies. In their well-nigh useless armour, which had been hacked from their limbs during their earlier encounters, the Greeks stood on a little hillock and braved the shower of Persian arrows and javelins. By the time the sun went down there remained not one of all the Grecian band, but before their death they had succeeded in slaying twenty thousand of the enemy. Xerxes inquired of Demaratus, in whose word he had come to have more confidence since witnessing the events of the last three days, whether there were many more men at Sparta like these; and when he was told that there were thousands, he realized that perhaps even his mighty army might not be a match for them. That all Greeks were not like the Spartans who had fallen at Thermopylae; that all Greek leaders were not as brave and as devoted as Leonidas--these facts Xerxes did not realize. The struggle which had proved so fatal to so many of his men had shown him that he was not so irresistible, and had thereby done much for the Greeks.