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.
Accordingly the Athenians sent it, on the pretence of their relationship, but really from a wish that no corn might be brought thence to the Peloponnese; and to make an experiment whether it were possible for them to bring Sicily into subjection to themselves.
Having established themselves therefore at Rhegium in Italy, they began the operations of the war in concert with their allies. And so the summer ended.
The following winter the plague a second time attacked the Athenians, having indeed never entirely left them, though there had been some abatement of it.
It lasted the second time not less than a year—the former attack having lasted two—so that nothing reduced the power of the Athenians more than this.
For not less than four thousand four hundred heavy-armed in the ranks died of it, and three hundred of the equestrian order, with a number of the multitude that was never ascertained.