History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
So the Athenians, after fortifying in six days the side towards the interior, and what most required it, left Demosthenes there with five ships to protect the place, while with the main body of the fleet they hastened on their voyage to Corcyra and Sicily.
When the Peloponnesians in Attica heard of the occupation of Pylus, they returned home with all speed; for the Lacedaemonians and Agis their king thought that the affair of Pylus closely affected them; and, besides, having made their incursion early in the season, and while the corn was still green, they were in want of provisions for most of their troops; while stormy weather, coming on with greater violence than was usual at that season, distressed the army.
So that for many reasons it happened that they returned quicker than usual, and that this was the shortest incursion they had made; for they remained in Attica but fifteen days.
At this same period, Simonides, an Athenian commander, having got together a few Athenians from the guard-stations, and a large body of the allies in that neighbourhood, took possession of Eion in Thrace, a colony from Mende, and hostile [to Athens], which was betrayed to him. But the Chalcidians and Bottiaeans having immediately come to its rescue, he was beaten out of it, and lost many of his soldiers.