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.
It is, in fact, as you must believe, a city that we are going forth to found amid alien and hostile peoples, and it behooves men in such an enterprise to be at once, on the very day they land, masters of the soil, or at least to know that, if they fail in this, everything will be hostile to them.