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.
During that day and the following night the Athenians kept them under guard; but on the next day, after setting up a trophy on the island, they made all their preparations to sail, distributing the prisoners among the trierarchs for safe-keeping; and the Lacedaemonians sent a herald and brought their dead to the mainland.
The number of those who had been killed or taken alive on the island was as follows: four hundred and twenty hoplites had crossed over in all; of these two hundred and ninety two were brought to Athens alive; all the rest had been slain. Of those who survived one hundred and twenty were Spartans.[*](ie. citizens of Sparta, the rest being from the neighbouring towns of the Perioeci; cf. 4.8.1.) Of the Athenians, however, not many perished; for it was not a pitched battle.
The time during which the men on the island were under blockade, from the sea fight up to the battle on the island, amounted all told to seventy-two days.
For about twenty of these days, the period during which the envoys were absent negotiating the truce, they were regularly provisioned, but the rest of the time they lived on what was smuggled in. And indeed some grain was found on the island at the time of the capture, as well as other articles of food;