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.

So the Athenian envoys returned to the army; and their generals, as the Melians would not yield, immediately commenced hostilities, and drew a wall round about the city of Melos, distributing the work among the several states.

Afterwards, leaving some of their own troops and of their allies to keep guard both by land and by sea, they withdrew with the greater part of the army, while the rest remained behind and besieged the place.