History of the Peloponnesian War

Being now therefore in possession of Oropus, the Eretrians came to Rhodes, inviting the Peloponnesians into Euboea. They, however, were more disposed to relieve Chios in its distress, and so put out and sailed from Rhodes with all their fleet.

When they were off Triopium, they descried that of the Athenians out at sea, sailing from Chalce: and as neither side advanced against the other, they arrived, the Athenians at Samos, the Peloponnesians at Miletus, finding that it was no longer possible to go to the relief of Chios without a sea-fight. And so the winter ended, and the twentieth year of this war of which Thucydides wrote the history.

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.