XI. He was elected general with unlimited powers, and proceeded to Platæa with eight thousand Athenians. Here he was met by Pausanias, the commander-in-chief of the Greek forces, with the Spartan contingent, and the rest of the Greek troops joined them there. The Persian army was encamped along the course of the river Asopus. On account of its enormous size it was not contained in a fortified camp, but a quadrangular wall was constructed round the baggage and most valuable material. Each side of this square was ten furlongs in length.

Tisamenus of Elis, the prophet, now told Pausanias and all the Greeks that they would win the victory if they stood on the defensive and did not attack. Aristeides sent to Delphi, and received a response from the oracle, that the Athenians would conquer if they prayed to Zeus, to Hera of Kithæron, and to Pan and the nymphs Sphragitides, and if they sacrificed to the heroes Androkrates, Leukon, Peisander, Damokrates, Hypsion, Aktaion, and Polyïdus, and if they would fight in their own territory, in the plain of Demeter of Eleusis and her daughter.

This oracle greatly disturbed Aristeides. The heroes to whom he was bidden to sacrifice are the original founders of the city of Platæa, and the cave of the nymphs called Sphragitides, is on one of the peaks of Kithæron, looking towards the point where the sun sets in summer. It is said that there was formerly an oracle there, and that many of the people became possessed, and were called "nympholeptæ." But as to the plain of the Eleusinian Demeter, and the promise of victory to the Athenians if they fought in their own country, this meant no less than to recall them to Attica and forbid their taking any further part in the war. Whilst Aristeides was thus perplexed, Arimnestus, the general of the Platæans, saw a vision in his sleep. In his dreams he thought that Zeus the Preserver appeared and enquired of him what the Greeks had decided to do, and that he answered, "Lord, to-morrow we shall lead away the army to Eleusis, and fight the Persians there, according to the oracle." Upon this the god answered, that they had missed the meaning of the oracle, for the places mentioned were near Platæa, where they themselves were encamped, and if they sought they would find them. Arimnestus, after this distinct vision, awoke. He at once sent for the oldest and most learned of the citizens of Platæa, and after debating the matter with them, discovered that near Hysiæ, under Mount Kithæron, stood a very ancient temple, dedicated to the Eleusinian Demeter and her daughter. He immediately took Aristeides with him and proceeded to the spot, which was excellently placed for the array of an infantry force in the presence of an overwhelming cavalry, because the spurs of Mount Kithæron, where they run down into the plain by the temple, render the ground impassable for cavalry. Close by is the chapel of the hero Androkrates, in the midst of a thick matted grove of trees. In order, however, that the oracle might in no way be defective in its promise of victory, Arimnestus proposed, and the Platæans decreed, that the boundary marks of their territory on the side towards Attica should be removed, and the country given to the Athenians, so that they might fight in their own land for Greece, according to the oracle. This noble act of the Platæans became so famous in later times, that, many years afterwards, Alexander the Great himself, when he had conquered all Asia, caused the walls of Platæa to be rebuilt, and made proclamation at the Olympian games by a herald, "that the king bestowed this honour upon the Platæans in memory of their magnanimous conduct in giving up their territory, and venturing their lives on behalf of the Greeks in the Persian war."

XII. A controversy arose between the Athenians and the men of Tegea about their respective places in the line of battle. The Tegeans argued that if the Lacedæmonians had the right wing, they ought to be posted on the left; and they spoke at great length about the achievements of their ancestors, as entitling them to that honour. The Athenians were vexed at their pretensions, but Aristeides said: "The present time is not suitable for disputing with the Tegeans about bravery; but to you, men of Sparta, and to the rest of the Greeks, we say that a particular post neither confers courage nor takes it away, but, that in whatever part of the line you may think fit to place us, we will endeavour so to array our ranks and fight the enemy as not to impair the honour which we have gained in former battles. We did not come hither to quarrel with our allies, but to fight the enemy; not to boast about our ancestors, but to fight bravely for Greece. The coming struggle will clearly show to all the Greeks the real worth and value of each city, each general, and each single citizen." When the council of generals heard this speech, they allowed the claim of the Athenians, and gave up the left wing to them.

XIII. While the cause of Greece was thus trembling in the balance, and Athens was especially in danger, certain Athenians of noble birth, who had lost their former wealth during the war, and with it their influence in the city, being unable to bear to see others exalted at their expense, met in secret in a house in Platæa and entered into a plot to overturn the free constitution of Athens. If they could not succeed in this, they pledged themselves to ruin, the city and betray it to the Persians. While these men were plotting in the camp, and bringing many over to their side, Aristeides discovered the whole conspiracy. Afraid at such a crisis to take any decisive step, he determined, while carefully watching the conspirators, yet not at once to seize them all, not knowing how far he might have to proceed if he acted according to strict justice. From all the conspirators he arrested eight. Two of these, who would have been the first to be put on their trial, Æschines of Lampra, and Agesias of Acharna, made their escape out of the camp, and Aristeides pardoned the others, as he wished to give an opportunity to those who believed themselves unsuspected, to take courage and repent. He also hinted to them that the war afforded them a means of clearing themselves from any suspicion of disloyalty by fighting for their country like good men and true.

XIV. After this, Mardonius made trial of Grecian courage, by sending the whole of his cavalry, in which he was much the stronger, to attack them where they were, all except the Megarians, encamped at the foot of Mount Kithæron, in an easily-defended rocky country. These men, three thousand in number, were encamped nearer the plain, and suffered much from the attacks of the horsemen, who surrounded them on all sides. They sent a messenger in great haste to Pausanias, begging him to send assistance, as they could not by themselves resist the great numbers of the barbarians. Pausanias, hearing this, and seeing the camp of the Megarians overwhelmed with darts and arrows, while the defenders were huddled together in a narrow compass, knew not what to do. He did not venture to attack cavalry with the heavy-armed Lacedæmonian infantry, but offered it as an opportunity for winning praise and honour, to the generals who were with him, that they should volunteer to go to help the Megarians in their extremity. All hesitated, but Aristeides claimed the honour for the Athenians, and sent the bravest of his captains, Olympiodorus, with three hundred picked men, besides some archers. As they quickly got into array and charged at a run, Masistius, the leader of the enemy, a man of great bodily strength and beauty, seeing them, wheeled round his horse, and rode to attack them. They sustained his attack and closed with his horsemen, and a sharp struggle took place, both parties fighting as though the issue of the war depended on their exertions. The horse of Masistius was at length wounded by an arrow and threw his rider. Encumbered by his armour, Masistius was too heavy for his own men to carry him away, but also was protected by it from the stabs of the Athenians who fell upon him, for not only his head and breast, but his limbs also were protected by brass and iron. Some one, however, drove the spike at the lower end of his spear through the eye-hole of the helmet, and then the rest of the Persians abandoned the body and fled. The Greeks discovered the importance of their exploit, not from the number of the dead, for but few had fallen, but from the lamentations of the enemy. They cut off their own hair, and the manes of their horses and mules, in sign of mourning for Masistius, and filled the whole plain with weeping and wailing, having lost a man who for courage and high position, was second only to Mardonius himself.

XV. After this cavalry action, both the parties remained quiet for a long time, for the soothsayers foretold victory both to the Greeks and to the Persians if they fought in self-defence, but foretold defeat if they attacked. At length Mardonius, as he only had provisions for a few days longer, and as the Greek army kept growing stronger by the continual reinforcements which it received, determined, sorely against his will, to delay no longer, but to cross the Asopus at daybreak and fall upon the Greeks unexpectedly. In the evening he gave orders to his captains to this effect. About midnight a solitary horseman rode up straight to the Greek camp. He bade the guard send for Aristeides the Athenian, who was at once brought, when the stranger spoke as follows:

"I am Alexander of Macedon, and I have come hither at the greatest risk to myself to do you a service, for fear you should be taken by surprise. Mardonius will attack to-morrow, not because he has any new hope of success, but because he is destitute of provisions, although the soothsayers all forbid him to fight because the sacrifices and oracles are unfavourable, and the army is disheartened. Thus he is forced to put all on a venture, or else to starve if he remains quiet." When he had said this, Alexander begged Aristeides to keep the secret to himself, and communicate it to no one else. Aristeides, however, answered that it would not be right for him to conceal it from Pausanias, who was commander-in-chief. Before the battle he said that he would keep it secret from every one else, but that if Greece was victorious, all men then should know the good service so bravely rendered by Alexander. After these words the king of Macedon rode away, and Aristeides, proceeding to the tent of Pausanias, told him the whole matter; they then sent for the other generals, and ordered them to keep the troops under arms, as a battle was expected.

XVI. At this time, Herodotus tells us, Pausanias asked Aristeides to remove the Athenians from the left to the right wing, so as to be opposite to the native Persian troops, on the ground that they would be better able to contend with them, because they understood their mode of fighting, and were confident because they had beaten them once before, while he with the Spartans would take the left wing of the army, where he would be opposed to those Greeks who had taken the Persian side. Most of the Athenian generals thought this a silly and insolent proceeding of Pausanias, that he should leave all the other Greeks in their place, and march them backwards and forward like helots, only to place them opposite the bravest troops of the enemy. Aristeides, however, said that they were entirely mistaken, for a few days before they had been wrangling with the Tegeans for the honour of being posted on the left wing, and had been delighted when they obtained it; but now, when the Lacedæmonians of their own free will yielded the right wing to them, and in some sort offered them the post of honour in the whole army, they were not delighted at it, and did not consider what an advantage it was to have to fight against foreign barbarians, and not against men of their own race and nation. After these words, the Athenians cheerfully exchanged places with the Lacedæmonians, and much talk went on among them as each man reminded his comrades that the Persians who would come to attack them were no braver, nor better armed than those whom they had defeated at Marathon, but that they had the same bows and arrows, the same embroidered robes and gold ornaments on their effeminate bodies, while we, they said, have arms and bodies such as we had then, and greater confidence because of our victories. We also fight, not merely as other Greeks do, in defence of our city and territory, but for the trophies of Marathon and Salamis, lest the battle of Marathon should be thought to have been won more by Miltiades and Fortune, than by the valour of the Athenians. With such encouraging talk as this the Athenians took up their new position; but the Thebans discovered what had been done from deserters and told Mardonius. He at once, either from fear of the Athenians, or from a chivalrous wish to fight the Spartans himself, led the native Persian troops to his right wing, and ordered the renegade Greeks to take ground opposite the Athenians. When these changes were being observed, Pausanias returned to his original position on the right. Mardonius then returned to the left as before, and the day passed without an engagement. The Greeks now determined in a council of war, to remove their camp to a place farther away and better supplied with water, because they were prevented from using the springs near where they were by the enemy's great superiority in cavalry.

XVII. When night fell the generals began to lead the army to the place selected for a new camp. The soldiers were very unwilling to follow them thither and keep together in a body, but as soon as they quitted their first entrenchments, most of them made for the city of Platæa; and there was much confusion as they wandered about and pitched their tents here and there. The Lacedæmonians, much against their will, chanced to be left behind, and quite separated from the rest. One Amompharetus, a spirited and daring man, who had long been eager to fight, and chafed much at the long delays and countermarches which had taken place, now cried aloud that this change of position was no better than a cowardly flight. He refused to leave his post, and said that he and his company would stand where they were, and withstand Mardonius alone. When Pausanias came and assured him that the Greeks in council had decided upon this measure, Amompharetus heaved up a huge stone with both his hands and flinging it down at the feet of Pausanias, said, "With this pebble I give my vote for battle, and for disregarding the cowardly counsels of other Greeks." Pausanias, not knowing what to do, sent to the Athenians, who were already on the march, begging them to wait and support them, while he set off with the rest of the Spartans in the direction of Platæa, hoping thus to make Amompharetus move.