History of the Peloponnesian War

Meanwhile the opponents of the traitors, being numerous enough to prevent the gates being opened to him at once, acting in concert with Eucles the general, who had come from Athens as warden of the place, sent to the other commander of the Thracian district, Thucydides son of Olorus, the author of this history, who was at Thasos, a Parian colony, about a half-day's sail from Amphipolis, and urged him to come to their aid.

And he, on hearing this, sailed in haste with seven ships which happened to be at hand, wishing above all to secure Amphipolis before it yielded, or, failing in that, to seize Eion.