History of the Peloponnesian War

The news of the revolt of these cities was likewise quickly brought to the Athenian people, who, hearing withal of the forces sent unto them under Aristeus, sent forth against the places revolted two thousand men of arms and forty galleys under the conduct of Callias, the son of Calliades.

These, coming first into Macedonia, found there the former thousand, who by this time had taken Therme and were now besieging the city of Pydna;

and staying, helped for a while to besiege it with the rest. But shortly after they took composition and, having made a necessary league with Perdiccas (urged thereto by the affairs of Potidaea, and the arrival there of Aristeus), departed from Macedonia.