History of the Peloponnesian War

The next summer, Alcibiades sailed to Argos with twenty ships, and seized three hundred men, who were still thought to be suspicious characters, and to favour the cause of the Lacedaemonians; and these the Athenians deposited in the neighbouring islands within their dominions. The Athenians also undertook an expedition against the island of Melos, with thirty ships of their own, six of the Chians, two of the Lesbians, sixteen hundred of their own heavy-armed, three hundred bowmen, twenty mounted archers, and about five thousand five hundred heavy-armed of the allies and the islanders.

Now the Melians are a colony of the Lacedaemonians, and would not submit to the Athenians, like the rest of the islanders, but at first remained quiet as neutrals, and then, when the Athenians tried to compel them by devastating their land, went openly to war with them.