History of the Peloponnesian War

About the same time, at the beginning of this winter, Sitalces the Odrysian, a son of Teres, king of the Thracians, made an expedition against Perdiccas son of Alexander, king of Macedonia, and against the Chalcidians of Thrace, wishing to exact fulfilment of one promise and to make good another.

For when Perdiccas was being hard pressed at the beginning of the war he had made Sitalces a promise on condition that he should reconcile him to the Athenians and should not bring back his brother Philip, who was hostile, to make him king; but Perdiccas would not fulfil his promise. On the other hand, Sitalces had made an agreement with the Athenians,[*](Thuc. 2.29.4.) at the time he entered into the alliance with them, to bring to an end their war with the Chalcidians in Thrace.

For both these reasons, then, he now began the invasion, and he took with him Philip's son, Amyntas,[*](Philip died meanwhile.) with a view to making him king of the Macedonians, as well as some Athenian envoys who had come to see him on this business, and Hagnon as commander[*](As commander of expected Athenian troops, which however failed to come (Thuc. 2.101.1).); for the Athenians were to furnish a fleet and as large an army as possible[*](Thuc. 1.101.1.) for the war against the Chalcidians.