History of the Peloponnesian War

The same winter the Athenians shut up Perdiccas in Macedonia [from the use of the sea], objecting that he had sworn the league of the Argives and Lacedaemonians; and that when they had prepared an army, under the command of Nicias, the son of Niceratus, to go against the Chalcideans upon Thrace and against Amphipolis, he had broken the league made betwixt them and him, and by his departure was the principal cause of the dissolution of that army, and was therefore an enemy. And so this winter ended, and the fifteenth year of this war.

The next summer went Alcibiades to Argos with twenty galleys and took thence the suspected Argives and such as seemed to savour of the Lacedaemonian faction, to the number of three hundred, and put them into the nearest of the islands subject to the Athenian state. The Athenians made war also against the isle of Melos, with thirty galleys of their own, six of Chios, and two of Lesbos. Wherein were of their own twelve hundred men of arms, three hundred archers, and twenty archers on horseback; and of their confederates and islanders, about fifteen hundred men of arms.