Those who were with Xerxes waited for a few days after the sea-fight and then marched away to Boeotia (department), Central Greece and Euboea, Greece, Europe Boeotia by the road by which they had come. Mardonius wanted to give the king safe conduct and thought the time of year unseasonable for war; it was better, he thought, to winter in +Thessaly [22.25,39.5] (region), Greece, Europe Thessaly, and then attack the +Peloponnese [22,37.5] (region), Greece, Europe Peloponnese in the spring.

When they had arrived in +Thessaly [22.25,39.5] (region), Greece, Europe Thessaly, Mardonius first chose all the Persians called Immortals, save only Hydarnes their general who said that he would not quit the king's person, and next, the Persian cuirassiers and the thousand horse and the Medes and Sacae and Bactrians and Indians, alike their infantrymen and the rest of the horsemen.

These nations he chose in their entirety; of the rest of his allies he picked out a few from each people, the best men and those whom he knew to have done some good service. The Persians whom he chose (men who wore torques and bracelets) were more in number than those of any other nation and next to them the Medes; these indeed were as many as the Persians, but not such stout fighters. Thereby the whole number, together with the horsemen, grew to three hundred thousand men.