Thermopylæ (the Hot Gates) consisted of two narrow passes, neither of them of greater width than one wheeled carriage would require, caused by the near approach of Mount Œta to the sea, or rather to an impassable morass which here formed the coast-line. (It is well to remark that considerable changes have taken place in the character of the country, the coast-line, in particular, having advanced a long way eastward.) The easternmost of the two passes was that to which the name properly belonged, for here there were actual hot springs, dedicated to Hercules, and supplying medicinal baths. Between the two passes (the distance of a mile) the mountain receded from the sea, leaving a level space of about half a mile broad. At Thermopylæ proper there was a wall built by the Locrians, but at the time of which we are speaking it had fallen into ruins.

It was here that Leonidas, one of the two kings of Sparta, took up his position, late, it would seem, in July. He had with him 300 Spartans, 2,500 soldiers from other parts of the Peloponnesus, a contingent of 700 from Thespiæ, one of the Boeotian towns, which dissented strongly from the pro-Persian views of their countrymen, and 400 Thebans, who came on compulsion. Thebes did not venture to refuse the demands of Leonidas while their Persian friends were still a long way off. He was also joined by contingents of the Locrians and Phocians. Both tribes had given in or were about to give in their submission to the Persians, but probably preferred the success of the Greeks. In any case, they were not prepared to resist the Greek commander-in-chief, present as he was with a much superior force.

Leonidas at once strengthened his position by repairing the half-ruined wall by the Hot Springs. But he learnt that Thermopylæ was not the only way by which access could be had from northern to southern Greece. The Phocians informed him that there was a mountain path which led from a point beyond the westernmost pass to another point beyond the defile of the Hot Springs. But they promised that they would guard it. The fact came, of course, to the knowledge of the troops generally, and greatly discouraged them. They even wished to abandon Thermopylæ altogether. Those that came from the Peloponnese were especially urgent, believing that they had a much better position for defence in the Isthmus of Corinth. Leonidas refused to retreat, but he sent messengers to the various Greek States with an urgent demand for reinforcements. The forces that he had with him were wholly unequal, he said, to cope with such an army as the Persians had at their command.

Xerxes, who had encamped within sight of Thermopylæ, sent a horseman to reconnoitre the position of Leonidas. The Spartans were on guard that day in front of the wall, and the man observed that some were engaged in athletic exercises, while others were combing their long hair. Demaratus, an exiled king of Sparta, who was with Xerxes, when questioned about the meaning of this behaviour, told him that his countrymen were particularly careful with their toilet when engaged in any dangerous enterprise, and that he must expect a desperate resistance. "You have to deal," he went on, "with the first city of Greece, and with her bravest men." "But how can so small a company contend with mine," asked Xerxes, who had not yet learnt to doubt his big battalions. The king was unwilling to believe him, and waited for four days in the expectation that the Greeks would think better of their purpose to resist, and would retire without a conflict.

On the fifth day, finding that the Greeks were still in their positions, Xerxes sent the Medes and the men of Cissia (now Khuzistan) with instructions to take the Greeks alive and bring them into his presence. These troops rushed with the greatest courage to the attack. Many were slain, for indeed they were no match for the Greeks in hand-to-hand fighting, but others stepped into their places. The struggle went on during the whole day, with no result except heavy loss to the assailants. On the morrow Xerxes sent his Persian corps d' elite, which went by the name of the "Immortals," to the attack, confident that they would be able to force the pass. They met with no better success. Their spears were shorter than those used by the Greeks, and the narrowness of the battlefield did not allow them to take advantage of their superiority in numbers. Herodotus makes special mention of the practised skill which the Spartans displayed. One of their methods was to feign flight, lure the assailants on, and then turn on them with deadly effect. Vast numbers of the Persians were slain; the Greeks also suffered some loss, for the best troops of the East could not have fought wholly in vain, but this loss was very small. Thrice during the day's engagement the Persian king is said to have leapt from the seat from which he watched the combat in terror for his army.

Yet another day was spent in a fruitless assault on the Greek position. The Persians hoped to wear out the enemy by incessant attacks. Some must be slain or wounded, and when the total number was so small, even a small loss must tell upon them in the end. As a matter of fact, however, the strength of the Greeks was not sensibly impaired. The space of ground that had to be held was very small, and the Greeks could change their men actually engaged at frequent intervals.

The treachery of a native of Malis, a little Dorian state in the heart of the mountains, relieved Xerxes of his perplexity. He offered, for a reward, to show a mountain path by which the Greek position could be turned. The name of this wretch, on whose head a price was set by the General Council of the Greek States, was Ephialtes. It is doubtful whether the secret could have been long kept; but there seems to have been a general agreement that Ephialtes was the guilty man, though other names were mentioned.

Xerxes willingly purchased the secret, and entrusted the task of outflanking the Greek position to the Immortals. They started at dusk and marched all night. The Phocian guards of the path seem to have neglected to place any outposts, and were not aware of the approach of the enemy till the crackling of the leaves under their feet, carried through the still air of night, gave them warning. They started up from their bivouack at the sound, and the Persians, surprised at the sight of an enemy whose presence they had not expected, halted. The Phocians seem not to have attempted to hold the path, but retreated to the crest of the hill and then made ready to defend themselves. The Persians left them alone, and continued their march.

The Greeks at Thermopylæ had by this time received warning of what had happened. The soothsayer attached to the force is said to have read in the victims which he examined a prognostic of their fate. More definite in-formation came from scouts who had been out on the hills, and who now came hurrying into the camp with the news. A council of war was hastily held. It could not agree, but the result was that the majority of the contingents retreated. Whether they did this with or with-out the orders of Leonidas is not certain. It is one of the matters about which it is almost impossible to arrive at the truth. Herodotus thinks that they were ordered to retire by Leonidas because he saw that they were unwilling to stay. This has a look of probability. As for Leonidas himself and his Spartans, they elected to stay. The inflexible military honour of their commonwealth forbade retreat. The seven hundred Thespians refused to depart, and must be allowed the glory of a still more heroic courage. The Theban contingent was detained against its will. The soothsayer Megistias—his name ought to be preserved no less carefully than that of the traitor Ephialtes—refused to depart, though being not a Spartan, but an Acamanian by birth, he might have done so without discredit; he sent away, however, his only son. The name of the Thespian leader ought also to have its place on the roll of honour. It was Demophilus.

In the forenoon the Persians began a double attack, in front and in rear. They had seen such proofs of Greek prowess that the men had to be driven into battle by the whip. As for the Greeks, they changed their tactics. Leaving the pass of the Hot Springs and the wall, they advanced into the open space. Hope of escape or victory had been given up. They would fight where they could sell their lives most dearly. And dearly did they sell them. Crowds of the Persians fell; many were trampled under foot by their comrades; many more were thrust into the marsh that bordered the road on the side of the sea. Among the slain were two brothers of the king. The Spartans and Thespians fought till their spears were broken. Leonidas seems to have fallen early in the day, and there was a furious struggle for the possession of his body. Four times did the barbarians carry it off, and four times was it recovered. As the day drew on the Immortals came upon the scene. Aware of their approach the Greeks retreated to the pass and prolonged their resistance to the very uttermost. When their weapons failed them they used their hands and even their teeth. But the Persians now surrounded them and showered arrows and all kinds of missiles upon them. They perished to a man. One more name from among the three hundred Spartans must be preserved—Dieneces, who seems to have been a wit as well as a warrior. When a man of Trachis told him that the Persians were so numerous that their arrows would darken the sun, "'Tis well," he replied, "stranger; then we shall fight in the shade." One of the contingent was absent. He and a comrade had been lying sick of ophthalmia at a neighbouring village. They could not agree as to what should be done. One buckled on his armour and bade his attendant helot lead him—for he could not see—to the battlefield. The helot did so, and then turned and fled. His master plunged into the thick of the fight and fell. The other sick man returned to Sparta. There no one would give him light to kindle his fire, or speak to him. He wiped away the reproach by falling, after prodigies of valour, at Platæa.