Three hundred thousand men, the picked troops of the army, Persians, Medes, Sacæ, Bactrians, and Indians, were left with Mardonius. They passed the winter in the friendly country of Thessaly. Before he moved his troops in the spring, the Persian general consulted the oracles of Northern Greece. What answers he received is not known. And he attempted to win over the power which had hitherto thwarted his master's purposes. A friendly prince, Alexander, king of Macedonia, was sent to offer terms to Athens. The proposal was met with a dignified refusal. "So long as the sun shall move in his accustomed way, so long will we stand against Xerxes," was the reply of the Athenian statesmen. The messenger was warned not to come again on the same errand. "Tempt us not to unfriendly acts; thou art a friend and guest; we would not willingly harm thee."

Sparta, aware of what Mardonius was doing, sent envoys to urge their allies to be steadfast in the cause of Greece. The reply was, that they need not fear; so long as there was an Athenian alive, no truce would be made with Xerxes. At the same time an earnest request was made that an army from the Peloponnesus should march in the early spring into Bœotia, and save Athens from a second destruction. Whether this help was promised, we are not told; it was certainly not given. With characteristic selfishness, the Peloponnesians, once assured that Athens would remain faithful, thought of nothing but their own safety, and laboured to complete the fortifications of the Isthmus.

It was late in the spring—May or, possibly, June—before Mardonius left his quarters in Thessaly, and marched into Bœotia. The Athenians again left their city, and the Persian general fixed his head-quarters in the Acropolis. He made a fresh attempt to win over these obstinate foes. The envoy met with a firm refusal. He was allowed to depart unhurt, but a senator, who ventured to suggest a consideration of the proposal, was stoned to death by his colleagues and the people, his wife and children meeting with the same fate at the hands of the Athenian women.

Another urgent demand for help was now addressed to Sparta. The Ephors continued to procrastinate, even in the face of the threat that Athens, if persistently deserted, must make terms for itself. For ten days an answer was postponed. On the eleventh the envoys presented a peremptory ultimatum, "Help us, or we secure our own safety." The Ephors replied, "An army is already on its march, and is even now beyond our borders." This statement they confirmed with an oath. And, indeed, their fears had at last been roused. An influential citizen of the Arcadian town of Tegea had warned them that the Isthmian wall would be useless if Athens was to put her fleet at the service of the invader. Then a sudden resolution was taken, and an effort not unworthy of the occasion was made, and made with astonishing speed. Sparta, always like a camp, was now, it is probable, prepared for instant action. An army of five thousand Spartans, each attended by seven armed Helots, and an equal number of Perioeci, each with one Helot, were actually on their march northward while the Ephors were speaking.

The Argives, always jealous rivals of Sparta, had promised Mardonius to arrest the march of their neighbours whenever it should take place. But this imposing force overawed them—and, indeed, never before or after was such an army brought together by the state. All that the Argives could do was to despatch their swiftest runner to the Persian general with tidings of what had happened. Mardonius evacuated Athens, not forgetting to complete the work of destruction before he departed, marched through the passes of Mount Parnes, and took up his position on the left bank of the river Asopus. On the other side of the stream he constructed a fortified camp of more than a square mile in extent. Behind this again he had a place of refuge in the strongly-fortified city of Thebes. To all appearance the chances of war were strongly in his favour. His army numbered more than three hundred thousand men, various contingents from Macedonia and northern tribes having joined in the course of the winter. Still the general feeling was anything but sanguine.

Herodotus illustrates this by a curious story which he heard, he declares, from an eye-witness, Menander of Orchomenus. It runs thus: The chief magistrate of Thebes invited to a great banquet fifty of the principal citizens together with fifty officers of the army, so disposing his guests that each couch accommodated a Persian and a Greek. "My neighbour," said Menander, "said to me, 'Since you have eaten at the same table and drunk of the same cup, hear the thing of which I am persuaded in my own mind; so you may best save yourself. See you these Persians that feast here, and the army which we left by the river? Out of them all in but a few days there shall survive but a very few!' This he spake with tears. Then I: 'Why tell you it not to Mardonius?' He replied: 'What God hath decreed none can avert. As for what I have said, no man will believe it. Verily of all things the most hateful is to know, and therewithal to have no power of doing aught!'"

Meanwhile the Greek army was gathering its strength. The force from Laconia numbered fifty thousand (ten thousand heavy-armed, and forty thousand light-armed). From the rest of the Peloponnese came about fourteen thousand, the most numerous contingent being the Corinthian, in which there were five thousand heavy-armed; Megara sent three thousand, and the Athenian heavy-armed numbered eight thousand. The total force was nearly one hundred and ten thousand, and it was under the command of the Spartan Pausanias. Crossing the ridge of the Cithæron, the Greeks came in view of the Persians, who were drawn up on the plain below. So formidable an appearance did the enemy present that Pausanias kept his army on the higher ground. Mardonius immediately assumed the offensive, sending his cavalry under Masistius to harass their movements. In cavalry the Greek army was absolutely deficient, nor could their archers contend on equal terms with the Persian bowmen. The Megarian contingent was particularly hard pressed, nor would any of the Greeks volunteer to go to their help. At last three hundred Athenians came forward and took up the task. The skirmish was decided by the fate of the Persian leader, Masistius. As he was charging at the head of his troop, his horse was struck by an arrow, reared, and threw him to the ground. Before he could rise the Athenians had rushed forward and seized him. Even then it was not easy to kill him, so impenetrable was his armour. At last an Athenian spear was driven into one of his eyes. A fierce struggle for his body followed it. The Persians recovered it for a time; then they lost it again. Finally it remained in Greek hands. There it was an object of the most lively curiosity, so splendid was the armour in which it was clad, so handsome the face and so magnificent the proportions of the dead man. In the Persian camp the loss of so renowned a leader caused the deepest grief. "The wailing for the dead could be heard," says the historian, "throughout the land of Bœotia."

This success encouraged Pausanias to leave the high ground, and to take up his position on the plain. The line was arranged according to the traditional order of precedence. The most honourable post, the right wing, was assigned, as a matter of course, to the Spartans; for the second in dignity, the left, there was a contest between Athens and Tegea. The Spartans, acting as arbiters, adjudged it to Athens. The remainder of the Greek forces occupied the centre, the Tegeans being next to the Spartans, and the Corinthians next again to them.

The new Greek position was by no means convenient. The whole army had to draw its supplies of water from a single spring near the right wing, for the Persian slingers and archers hindered access to the river Asopus. At the same time the Persian cavalry cut off the convoys that brought supplies from the Peloponnesus, while the soothsayers declared that the omens were unfavourable to a forward movement.

What would have been the result if Mardonius had followed the policy of delay, urged upon him by his Theban allies, while he continued to use his superiority in cavalry to annoy his adversaries, it is impossible to say. Happily his impatience was too strong for him, and he determined to attack. Alexander of Macedon, anxious to secure friends on both sides, warned the Greeks of what was to happen, and Pausanias, in view of it, proposed to the Athenians that they should change places with the Spartan troops. As the two armies were now arranged, the Spartans faced the Persians, the Athenians the Greek allies of Xerxes. This Pausanias proposed to change. "We," he said to the Athenians, "have never had to do with the Persian troops, whereas you conquered them at Marathon. Do you therefore take our place, and we will deal with the hostile Greeks, adversaries to whom we are accustomed." The proposal was accepted, and the movement was begun. It did not, however, escape the notice of Mardonius, and as he made a corresponding change it his own line, the old order was resumed.

Meanwhile the second position became untenable. The Persian skirmishers made even the single spring on which the army depended impossible of access and it became necessary to move. It was resolved to take up a third position on a so-called "island" made by two branches of the Oeroe, a small stream that ran westward into the Corinthian Gulf. Difficulties and disagreements that might easily have ended in disaster arose when the time came for executing this movement. The Greeks of the centre, distressed and alarmed by the incessant attacks of the Persian cavalry, which had become bolder since the manœuvre attempted by the Spartans, disobeyed orders, and marched, not to the island, but to the town of Platæa, where they found a safer position. Disobedience of another kind hampered the Spartans; the leader of one of the divisions flatly refused to move. "You are flying from the enemy," he said, "and this is a thing that the true Spartan can never do." Threats and persuasions were lost upon him; go he would not, not even if he and his division were left to fight the barbarians alone. At daybreak, while the dispute was still raging, an Athenian messenger rode up to ask whether the Spartans intended to carry out the proposed plan. Pausanias pointed to the refractory captain as the cause of the delay, and bade the messenger carry back to his chief the story of the untimely obstinacy which was endangering the common safety. Amompharetus—this was the dissentient captain's name—still refused to yield. Taking up a small boulder from the ground he cast it down at the feet of Pausanias with the words, "I give my vote for staying here." At last Pausanias made up his mind to move, leaving the obstinate officer to act as he pleased. He had not been gone long before Amompharetus followed him.

But valuable time had been lost, while the hopes of the Persians, who fancied that the Greeks had lost courage, rose high. They followed the seemingly retreating Spartans in hot haste, and overtook them just as they were joined by the division of Amompharetus. So hot was the attack that Pausanias sent messengers to the Athenians, asking for help. But these were by this time engaged with the Greek allies of Xerxes, and could for the present do no more than hold their own.

For a time the battle seemed to go against the Spartans and Tegeans; these latter, alone of all the Greeks of the centre, had kept their place. The Persians made a breastwork of their wicker shields, and poured from behind it an incessant stream of arrows, strongly propelled by their gigantic bows, upon the line of the Greeks. These for the time could do nothing but endure. The victims gave no favourable signs, and without these Pausanias did not venture to move. It was not till, wearied of this disastrous delay, he turned to the neighbouring shrine of Heré and implored the goddess to help him, that the omens changed, and the welcome order to charge was given. The Tegeans, less patient or less superstitious, had already advanced, and the two armies closed in a furious struggle. But the time for the bow was over; the triumph of the spear was come. In vain did the Persians fling themselves with desperate courage on the foe, actually grappling with them in close embrace. The Greeks were practised soldiers and athletes, and they were protected, as far as the most vital parts were concerned, by armour. No valour could avail against such odds, and the battle was soon decided. The Persians fled in headlong confusion to their camp, hotly pursued by their adversaries, who, now that the victory was practically won, were joined by some of the other Greek contingents.

The Athenians meanwhile had had a harder task, matched as they were with the Greek allies of Mardonius. Foremost among these were the Thebans, a race whose stubborn courage changed more than once the course of Greek history. Others were probably less resolute, the Phocians especially, whose fidelity to a cause which they had espoused under compulsion, had already been doubted. After a stout resistance the Greek allies of Mardonius retired, but in good order, and the Athenians were free to join their allies in the attack upon the camp. In this no progress had been made, so unskilled were the Spartans in all fighting not carried on in the open field. The Athenians brought with them some knowledge of siege operations, and it was not long before the camp was stormed. A frightful massacre followed, the conquerors slaying without mercy till their arms were weary. Mardonius and his bodyguard of a thousand Immortals had perished earlier in the day; before nightfall the huge Persian host had practically ceased to exist. It was said that only three thousand were left alive. It must be remembered, however, that one of the subordinate commanders, Artabanus by name, had separated his own force of sixty thousand from the enemy before the battle commenced. He hurried with them northwards, as speedily as possible, and was able to reach Asia in safety. Of the Greeks one hundred and fifty-nine fell, the losses being thus divided, of the Lacedæmonians nine-one, of the Tegeans sixteen, of the Athenians fifty-two. The other Greeks had practically no share in the battle though, several cities bribed the Platæans, who were constituted guardians of the field, to allow them to erect monumental barrows.

Plutarch, it is true, says that the total loss of the Greeks was one thousand three hundred and sixty. To make up this number we must add those that fell in the movements before the battle, and six hundred Megarians, who were cut off by the Theban cavalry and, as Herodotus says, "perished without honour." This makes a total of seven hundred and fifty-nine. The difference between this and Plutarch's figure, (six hundred) may, perhaps, be accounted for by reckoning in the Helots or light-armed troops who accompanied the Spartan and Periœci. Of these there were forty thousand on the field. Herodotus gives the Spartan  loss only.