Meanwhile Sitalces opened negotiations with Perdiccas on the objects of his expedition; and finding that the Athenians, not believing that he would come, did not appear with their fleet, though they sent presents and envoys, dispatched a large part of his army against the Chalcidians and Bottiaeans, and shutting them up inside their walls laid waste their country. While he remained in these parts, the people farther south, such as the Thessalians, Magnetes, and the other tribes subject to the Thessalians, and the Hellenes as far as Thermopylae, all feared that the army might advance against them, and prepared accordingly. These fears were shared by the Thracians beyond the Strymon to the north, who inhabited the plains, such as the Panaeans, the Odomanti, the Droi, and the Dersaeans, all of whom are independent. It was even matter of conversation among the Hellenes who were enemies of Athens whether he might not be invited by his ally to advance also against them. Meanwhile he held Chalcidice and Bottice and Macedonia, and was ravaging them all; but finding that he was not succeeding in any of the objects of his invasion, and that his army was without provisions and was suffering from the severity of the season, he listened to the advice of Seuthes, son of Spardacus, his nephew and highest officer, and decided to retreat without delay. This Seuthes had been secretly gained by Perdiccas by the promise of his sister in marriage with a rich dowry. In accordance with this advice, and after a stay of thirty days in all, eight of which were spent in Chalcidice, he retired home as quickly as he could; and Perdiccas afterwards gave his sister Stratonice to Seuthes as he had promised. Such was the history of the expedition of Sitalces.