History of the Peloponnesian War

Immediately at the commencement of the spring of the following summer, Dercyllidas, a Spartan, was sent with a small force by land to the Hellespont, to effect the revolt of Abydus, which is a colony of the Milesians; and the Chians, while Astyochus was at a loss how to succour them, were compelled by the pressure of the siege to a naval engagement.

They happened, while Astyochus was still at Rhodes, to have received from Miletus, as their commander after the death of Pedaritus, a Spartan named Leon, who had come out as a passenger with Antisthenes, and twelve ships which had been on guard at Miletus, five of which were Thurian, four Syracusan, one Anaean, one Milesian, and one Leon's own ship When therefore the Chians had gone out against them in full force, and had occupied a strong position, while their ships at the same time to the number of six and thirty put out to meet the two and thirty of the Athenians, they engaged them by sea;

and an obstinate battle having been fought, the Chians and their allies, who had not the worst in the action, returned (for it was now late) into their city.