The leader of those who were opposed to Themistocles was Aristides, a man so upright that he was often called "the Just." He also had met the Persians at Marathon, and he honestly believed that Themistocles was in the wrong. "It is our victories on land that have made us strong," he said to himself, "and shall we intrust our safety to the perils of the ocean?" He and his party opposed Themistocles so strongly that perhaps not one new vessel would have been built if war had not broken out between Athens and Ægina. Ægina was so much better supplied with ships than Athens, and Athens so felt the need of them in this war, that little by little the Athenians began to think that Themistocles might be in the right. At last the opposition between the two parties became so bitter that the matter was brought to the test of ostracism. The story is told that while Aristides stood watching the voters drop their shells and bits of potsherd into the urns, a stranger said to him, "I cannot write. Will you put the name of Aristides on my ostrakon?" "What wrong has he ever none you?" Aristides asked; and the man replied, "None, but I am tired of hearing him called 'the Just.'" Aristides said no more, but quietly wrote his name. The vote was against him, and he went into exile.

Even then the ships were not built at once, for shipbuilding is always expensive, and where the money was to come from was a question. Fortunately, a large sum came into the Athenian treasury just then from some rich silver mines. "Give this money to build a fleet," Themistocles pleaded, and at last the ships were built. Piræus, the port of Athens—for the city was four miles from the sea—was fortified, or rather, partially fortified; for before the work was completed the Persians were on their way for a third invasion of Greece.

When the ships of Darius had come home without the plunder and the troops of prisoners that the king had expected, and he learned of the battle of Marathon, he was a very angry sovereign. Twice the Persian forces had crossed into Europe, and twice they had been driven back. They should go again, and he himself would go with them. Those haughty Athenians should learn how kings of Persia treated the insolent tribes that dared oppose them. He began to make ready. He sent to the cities that he had conquered and ordered them to assemble men and horses and ships, and to provide great stores of grain. For three years the preparations went on; then Darius suddenly died.

Xerxes, son of Darius, became king. He was satisfied with the size of his kingdom, and he would rather have stayed at home. His counselors, however, were of another mind. Mardonius in particular, who had led the first expedition against the Greeks, was eager to show that, even if he had failed once, he was, nevertheless, a skillful general.

Xerxes decided to make the expedition, and he meant that it should succeed. There must be no wrecking of ships on Mount Athos, so he had a canal dug straight across the peninsula. The land forces must cross the Hellespont, and there he had two bridges of boats built. A little later the great king was in a great passion, for a storm had swept away his bridges. He bade his men give the Hellespont three hundred lashes for its insolence in daring to break down his work, and he ordered the heads of the builders to be cut off. Then he did one thing that was decidedly more sensible—he set to work to make stronger bridges. First, boats were anchored side by side until the space between the two shores was filled. Then six enormous cables were stretched from shore to shore, resting on the decks of the vessels. Upon these were laid logs, then planks, and then earth. Everything was firmly fastened; and last of all, a palisade was built on both sides, so high that the horses and cattle could not be frightened by seeing that the water was under them. The second bridge was built in the same fashion.

When the bridges were done, the canal cut, and stores of food deposited in different places along the way that Xerxes intended to take, he marched out from his capital. For a little while he was a badly frightened monarch, for the sun went into eclipse. "What does it mean?" he demanded of his wise men, in terror. "Fear not, O great king," they replied; "the sun gives warning to Greeks, but the moon to Persians. The sun has vanished from the heavens, and so will the cities of the Greeks vanish from the earth." Then the king marched on.

When the army came to the Hellespont, there stood on the top of a hill a white marble throne which Xerxes had ordered to be made ready for him. He took his seat on the throne. Below him were hundreds of vessels and uncounted thousands of men, the greatest land and sea force that ever came together. Xerxes always enjoyed a spectacle. He gazed and gazed, at the sea, at the shore, and again at the sea; and the thought that was uppermost in the mind of this royal commander was that it was an excellent opportunity for a boat-race! The race was held and greatly delighted the king. He was still more pleased as he looked again upon his troops. All at once he began to weep. "There came upon me a sudden pity," he said, "when I thought of the shortness of man's life and considered that of all this host so numerous as it is, not one will be alive when a hundred years are gone by." This was all true, but no efficient commander would have had leisure at such a time for either boat-races or philosophy.

On the following day the invaders were to cross the Hellespont. Long before light the Persians were burning spices on the bridge of boats and strewing the way with myrtle boughs. They kept close watch of the eastern sky, for the sun was their god, and if it rose clear and bright, they might look for success. When the first rays dazzled their eyes, they rejoiced, and Xerxes poured out an offering of wine from a golden goblet. "O Ormuzd," he cried, "I pray thee that no misfortune may hinder me from conquest until I have made my way to the uttermost boundaries of Europe." He cast into the Hellespont the golden goblet, a golden bowl, and a sword; and then the army began to cross.

This was the most magnificent procession ever seen in the world. There were the Ten Thousand Immortals, the special guard of the king, marching steadily and gravely, with crowns on their heads. One thousand of them carried spears with golden pomegranates at the lower end, and nine thousand bore spears tipped with pomegranates of silver. There were the ten sacred horses all richly caparisoned. There was the holy chariot of Ormuzd, the sun-god, drawn by eight milk white steeds. So revered was this chariot that not even the charioteer was allowed to enter it, but must drive as best he could walking behind it. After the chariot of Ormuzd came that of Xerxes, drawn by great horses. There were Persians and Medes, with iron coats of mail, bows and arrows, short spears and daggers, and big wicker shields. There were Assyrians with brazen helmets and linen corselets and clubs knotted with iron. There were Sacæ with tall pointed caps; Sarangians in garments of the most gorgeous coloring; Ethiopians of the West, their bodies painted half red and half white; Ethiopians of the East, who wore on their heads the scalps of horses, the ears pricked up and the mane serving as a crest. There were Colchians with wooden helmets and little rawhide shields: Thracians with their long cloaks and on their heads the skins of foxes; Chalybeans, whose brazen helmets were made in the shape of an ox's head. There were chariots and horses and camels and servants and long trains of provisions. Everything of metal was burnished and shining; and the Persians, especially, wore so many golden ornaments that their lines fairly glittered.

Over the bridges they went, and for seven long days and nights the people who lived about the Hellespont heard the tramp, tramp of marching feet. Having passed the bridges, the land forces moved on to Doriscus in Thrace where the ships, too, were to assemble. Here it was that Xerxes numbered his forces. This is the way he did it. Ten thousand me were crowded together in circle. Then a pen was built just the size of the circle and filled with men. The were enough foot-soldiers to fill it one hundred and seventy times, making 1,700,000. The horsemen were 80,000. Xerxes drove in his chariot about the plain, from nation to nation. Then he stepped into a galley, and, sitting beneath a golden canopy, he watched the vessels as they passed him single file. After the first this review must have been rather tiresome, for there were 1207 warships, besides about 3000 smaller vessels and ships of burden.

There seemed to be forces enough to sweep the little country of Greece off the face of the earth. Xerxes sent for a Greek who had been driven by his countrymen from the throne of Sparta, and said, "Demaratus, my opinion is that even if the Greeks were all gathered together, they could not resist my attack but what do you think?" Demaratus asked, "O king, shall I give you a true answer, or do you wish only for a pleasant one?" "Speak the plain truth," bade the king, "and I shall hold you in no less favor." Then Demaratus told him that, however it might be with other tribes, the Spartans, at least, would never become his slaves. "If there were only one thousand of them," he declared, "they would not flee, but would come out boldly and meet your whole army in battle." King Xerxes laughed and sent him away with words of kindness.

The army grew larger as it went on, for the tribes that had been conquered by the Persians in the earlier invasions were obliged to furnish soldiers. Long before this, warning had been sent to the towns along the road that they must provide food for the army. They did not dare to refuse, and for many months they had been hard at work making ready. Wheat and barley must be ground, cattle and poultry must be bought and fattened. These were for the army; but the townsfolk knew well that if they would win the favor of Xerxes, they must also prepare an elaborate banquet for him and his friends. On such a banquet one town spent $500,000, and other towns spent nearly as much. The army ate the country bare and actually drank the rivers dry, leaving behind them only little muddy brooks trickling down the empty channels.

Whether to go through the Pass of Tempe in Thessaly, or another one farther from the shore, was the question. Xerxes went aboard one of his ships and made a short voyage, so that he could see Tempe from the water. He anchored off the Thessalian coast, and stood gazing at the shore. Before him rose mighty cliffs. In the cliffs was a narrow cleft through which a river was flowing into the sea. "Is there no other outlet for the river?" he asked. "None, O king, was the reply, "for Thessaly is girt all about with a circlet of mountains." "They were wise men, then, those Thessalians," said the king, "to submit to me in time. I could easily fill up that gorge and turn the whole country into a lake." Xerxes sailed back to his army; but before going any farther he dispatched heralds to the various states, demanding earth and water. No heralds were sent to either Athens or Sparta, because of the way they had treated those sent previously.

The Greeks had been watching the movements of Xerxes as a mouse might watch those of a cat. "He is making vast preparations; he is at Sardis in Lydia; he is at the Hellespont; he has crossed"; such were the reports that came to them. Some states decided at once to yield to the mercy of the Persian king and sent him earth and water. The Athenians knew well that no mercy would be shown them. They knew, too, that there was no hope of success in resisting the Persians if they had to stand alone. Therefore they asked the different states to send envoys to a council to be held at Corinth. Some sent; some did not. The Spartans were looked upon as the best soldiers of Greece, and they would naturally lead the army; but Argos would have nothing to do with any union unless her king could share the command. Thebes would not agree to anything proposed by Athens. Messengers had also been sent to the larger colonies, asking them to help save the mother country from the barbarians. "If Greece is conquered," they said, "the Persians will then fall upon you. Save yourselves by saving Greece." Gelo, tyrant of Syracuse in Sicily, sat listening to the message. He replied, "Yes, I will send you two hundred ships of war and twenty-eight thousand men, and I will supply food for the whole army as long as the war lasts; but I, Gelo of Syracuse, must then be leader and commander." "The command belongs to Sparta," declared the messengers. "If you will not follow our lead, send us no troops." "I have forces many times as great as those of Sparta," said Gelo, "but I will yield and be content to command either on sea or on land."

Then the Athenian envoys stood for their own rights. "We are the oldest nation in Greece," they said, "we dwell where we have always dwelt; we have the largest fleet; even at Troy our leader was famous for his skill; and if the Spartans yield the command of the sea to any one, it is ours." Gelo retorted, "You are likely to have more commanders than men. The sooner you return the better."

Athens, Sparta, Platæa, and other states that had agreed to stand together saw that they could hope for no strength but their own. The Athenians sent messengers to Delphi. The oracle was as confusing as the oracles usually were, and the only statement that seemed clear was that the enemy would capture Athens. One line in particular the Athenians discussed over and over. It was, "Safe shall the wooden walls continue for thee and thy children." Some recalled the fact that in the early days the Acropolis was fortified by a wooden palisade. "Whatever happens," they said, "we can take refuge on the Acropolis." Themistocles declared that "wooden walls" meant their ships; and finally most of the Athenians came to agree with him.

Themistocles urged the Athenians to build ships. Aristides was ostracized, and after a time the ships were built.

Darius made ready for a third expedition against Greece. At his death his son Xerxes took his place. He dug a canal across the peninsula of Mount Athos, bridged the Hellespont, and stored food in various places along what was to be his line of march. He halted at the Hellespont, reviewed his fleet, and held a boat-race, then crossed the Hellespont. At Doriscus in Thrace the land and sea forces met. There Xerxes numbered his men. Towns along the way were forced to feed the Persians. Xerxes visited the Pass of Tempe. He demanded earth and water of the Greek states. Some yielded.

The Athenians called a council of states at Corinth. The colonies were also appealed to. Some refused out of jealousy, among them Gelo, tyrant of Syracuse.

The oracle promised safety in the "wooden walls."

An Athenian tells why he voted against Aristides.

A Persian soldier describes the crossing of the Hellespont.

Two Athenians discuss the meaning of the oracle.