History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
On reaching Epidaurus in the Peloponnesus the Athenians ravaged most of that land; they also attacked the city, but, though they at first had hopes of taking it, they did not succeed.
Then, leaving Epidaurus, they went to sea again, and ravaged the territory of Troezen, Halieis, and Hermione, which are all on the Peloponnesian coast.
Sailing next from this region they came to Prasiae, a town on the coast of Laconia, where they not only ravaged parts of the country, but also captured the town itself and pillaged it. After they had completed these operations they went back home, where they found that the Peloponnesians were no longer in Attica but had retired.
During this entire period, while the Peloponnesians were in Attica and the fleet of the Athenians was on the expedition, the plague was making havoc among the Athenians, both in their fleet and in the city. The statement was therefore made that the Peloponnesians left Attica in haste because they were afraid of the disease, since they not only heard from deserters that it was in the city, but also could see them burning their dead.
In this invasion, however, they remained in Attica longer than at any other time, and also ravaged the entire country; indeed they were in Attica almost forty days.