The Histories by Herodotus — Book VIII, The portent at Eleusis

Dicaeus son of Theocydes, an Athenian exile who had become important among the Medes, said that at the time when the land of Attica was being laid waste by Xerxes' army and there were no Athenians in the country, he was with Demaratus the Lacedaemonian on the Thriasian plain and saw advancing from Eleusis a cloud of dust as if raised by the feet of about thirty thousand men. They marvelled at what men might be raising such a cloud of dust and immediately heard a cry. The cry seemed to be the “Iacchus” of the mysteries, ^65.2and when Demaratus, ignorant of the rites of Eleusis, asked him what was making this sound, Dicaeus said, “Demaratus, there is no way that some great disaster will not befall the king's army. Since Attica is deserted, it is obvious that this voice is divine and comes from Eleusis to help the Athenians and their allies. ^65.3If it descends upon the Peloponnese, the king himself and his army on the mainland will be endangered. If, however, it turns towards the ships at Salamis, the king will be in danger of losing his fleet. ^65.4Every year the Athenians observe this festival for the Mother and the Maiden, and any Athenian or other Hellene who wishes is initiated. The voice which you hear is the ‘Iacchus’ they cry at this festival.” To this Demaratus replied, “Keep silent and tell this to no one else. ^65.5If these words of yours are reported to the king, you will lose your head, and neither I nor any other man will be able to save you, so be silent. The gods will see to the army.” ^65.6Thus he advised, and after the dust and the cry came a cloud, which rose aloft and floated away towards Salamis to the camp of the Hellenes. In this way they understood that Xerxes' fleet was going to be destroyed. Dicaeus son of Theocydes used to say this, appealing to Demaratus and others as witnesses.

^66.1When those stationed with Xerxes' fleet had been to see the Laconian disaster at Thermopylae, they crossed over from Trachis to Histiaea, waited three days, and then sailed through the Euripus, and in three more days they were at Phalerum, the port of Athens. I think no less a number invaded Athens by land and sea than came to Sepias and Thermopylae. ^66.2Those killed by the storm, at Thermopylae, and in the naval battles at Artemisium, I offset with those who did not yet follow the king: the Melians and Dorians and Locrians and the whole force of Boeotia except the Thespians and Plataeans; and the Carystians and Andrians and Teneans and all the rest of the islanders, except the five cities whose names I previously mentioned. The farther into Hellas the Persian advanced, the more nations followed him.

^67.1All these came to Athens except the Parians. The Parians stayed behind in Cythnus watching to see which way the war turned out. When the rest of them reached Phalerum, Xerxes himself went down to the ships, wishing to mix with the sailors and hear their opinions. ^67.2He came and sat on his throne, and present at his summons were the tyrants of all the peoples and the company leaders from the fleet. They sat according to the honor which the king had granted each of them, first the king of Sidon, then the king of Tyre, then the rest. When they sat in order one after another, Xerxes sent Mardonius to test each by asking if they should fight at sea.

⁶⁸Mardonius went about questioning them, starting with the Sidonian, and all the others were unanimous, advising to fight at sea, but Artemisia said,

^68A.1“Tell the king, Mardonius, that I, who neither was most cowardly in the sea battles off Euboea nor performed the least feats of arms, say this: ‘Master, it is just for me to declare my real opinion, what I consider to be best for your cause. And I say to you this: spare your ships, and do not fight at sea. Their men are as much stronger than your men by sea as men are stronger than women. ^68A.2Why is it so necessary for you to risk everything by fighting at sea? Do you not possess Athens, for which you set out on this march, and do you not have the rest of Hellas? No one stands in your way. Those who opposed you have received what they deserved.

^68B.1I will tell you how I think the affairs of your enemies will turn out: If you do not hurry to fight at sea, but keep your ships here and stay near land, or even advance into the Peloponnese, then, my lord, you will easily accomplish what you had in mind on coming here. ^68B.2The Hellenes are not able to hold out against you for a long time, but you will scatter them, and they will each flee to their own cities. I have learned that they have no food on this island, and it is not likely, if you lead your army against the Peloponnese, that those of them who have come from there will sit still, nor will they care to fight at sea for Athens.

^68CBut if you hurry to fight at sea immediately, I fear that your fleet if reduced to cowardice may also injure your army on land. In addition, my King, take this to heart: Good people's slaves tend to be base, and the slaves of the base tend to be good. You, who are best among men, have base slaves, who are accounted your allies, the Egyptians and Cyprians and Cilicians and Pamphylians, who are of no use at all.’”

^69.1When she said this to Mardonius, all who were well disposed towards Artemisia lamented her words, thinking she would suffer some ill from the king because she advised against fighting at sea. Those who were jealous and envied her, because she was given honor among the chief of all the allies, were glad at her answer, thinking she would be killed. ^69.2But when the counsels were reported to Xerxes, he was greatly pleased by Artemisia's opinion. Even before this he had considered her of excellent character, and now he praised her much more highly. Still he ordered that the majority be obeyed, for he believed that at Euboea they had purposely fought badly because he was not there. This time he had made preparations to see the battle in person.

^70.1When the command to put out to sea was given, they set sail for Salamis and were calmly marshalled in line. There was not enough daylight left for them to fight, since night came on, so they made preparations for the next day. ^70.2Fear and dread possessed the Hellenes, especially those from the Peloponnese. They were afraid because they were stationed in Salamis and were about to fight at sea on behalf of the land of the Athenians, and if they were defeated they would be trapped on an island and besieged, leaving their own land unguarded.