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.

For they were distressed by sickness for a double cause, the season of the year being that in which men are most liable to illness, while at the same time the place in which they were encamped was marshy and unhealthy; and the situation in general appeared to them to be utterly hopeless.