Nevertheless, three years after, when Xerxes marched through Thessaly and Boeotia into the country of Attica, repealing the law, they decreed the return of the banished: chiefly fearing Aristides, lest, joining himself to the enemy, he should corrupt and bring over many of his fellow-citizens to the party of the barbarians; much mistaking the man, who, already before the decree, was exerting himself to excite and encourage the Greeks to the defence of their liberty. And afterwards, when Themistocles was general with absolute power, he assisted him in all ways both in action and counsel;rendering, in consideration of the common security, the greatest enemy he had the most glorious of men. For when Eurybiades was deliberating to desert the isle of Salamis, and the galleys of the barbarians putting out by night to sea surrounded and beset the narrow passage and islands, and nobody was aware how they were environed, Aristides, with great hazard, sailed from Aegina through the enemy's fleet; and coming by night to Themistocles's tent and calling him out by himself; "if we have any discretion," said he, "Themistocles, laying aside at this time our vain and childish contention, let us enter upon a safe and honourable dispute, vying with each other for the preservation of Greece; you in the ruling and commanding, I in the subservient and advising part; even indeed, as I now understand you to be alone adhering to the best advice, in counselling without any delay to engage in the straits. And in this, though our own party oppose, the enemy seems to assist you. For the sea behind, and all around us, is covered with their fleet; so that we are under a necessity of approving ourselves men of courage, and fighting whether we will or no; for there is no room left us for flight." To which Themistocles answered, "I would not willingly, Aristides, be overcome by you on this occasion; and shall endeavour, in emulation of this good beginning, to outdo it in my actions." Also relating to him the stratagem he had framed against the barbarians, he entreated him to persuade Eurybiades and show him how it was impossible they should save themselves without an engagement; as he was the more likely to be believed. Whence, in the council of war, Cleocritus, the Corinthian, telling Themistocles that Aristides did not like his advice as he was present and said nothing, Aristides answered, That he should not have held his peace if Themistocles had not been giving the best advice; and that he was now silent not out of any good-will to the person, but in approbation of his counsel.
Thus the Greek captains were employed. But Aristides perceiving Psyttalea, a small island that lies within the straits over against Salamis, to be filled by a body of the enemy, put aboard his small boats the most forward and courageous of his countrymen, and went ashore upon it; and, joining battle with the barbarians, slew them all, except such more remarkable persons as were taken alive.
Amongst these were three children of Sandauce, the king's sister, whom he immediately sent away to Themistocles, and it is stated that, in accordance with a certain oracle, they were by the command of Euphrantides, the seer, sacrificed to Bacchus, called Omestes, or the devourer. But Aristides, placing armed men all around the island, lay in wait for such as were cast upon it, to the intent that none of his friends should perish, nor any of his enemies escape.
For the closest engagement of the ships, and the main fury of the whole battle, seems to been about this place; for which reason a trophy was erected in Psyttalea.
After the fight, Themistocles, to sound Aristides, told him they had performed a good piece of service, but there was a better yet to be done, the keeping Asia in Europe, by sailing forthwith to the Hellespont and cutting in sunder the bridge. But Aristides, with an exclamation, bid him think no more of it, but deliberate and find out means for removing the Mede, as quickly as possible, out of Greece; lest being enclosed, through want of means to escape, necessity should compel him to force his way with so great an army. So Themistocles once more despatched Arnaces, the eunuch, his prisoner, giving him in command privately to advertise the king that he had diverted the Greeks from their intention of setting sail for the bridges, out of the desire he felt to preserve him.
Xerxes, being much terrified with this, immediately hasted to the Hellespont. But Mardonius was left with the most serviceable part of the army, about three hundred thousand men, and was a formidable enemy, confident in his infantry and writing messages of defiance to the Greeks: "You have overcome by sea men accustomed to fight on land, and unskilled at the oar; but there lies now the open country of Thessaly; and the plains of Boeotia offer a broad and worthy field for brave men, either horse or foot, to contend in." But he sent privately to the Athenians, both by letter and word of mouth from the king, promising to rebuild their city, to give them a vast sum of money, and constitute them lords of all Greece, on condition they were not engaged in the war. The Lacedaemonians, receiving news of this, and fearing, despatched an embassy to the Athenians, entreating that they would send their wives and children to Sparta, and receive support from them for their superannuated. For, being despoiled both of their city and country, the people were suffering extreme distress.