History of the Peloponnesian War (1.1.1-1.1.3)

Thucydides, an Athenian, wrote the history of the war waged by the Peloponnesians and the Athenians against one another. He began the task at the very outset of the war, in the belief that it would be great and noteworthy above all the wars that had gone before, inferring this from the fact that both powers were then at their best in preparedness for war in every way, and seeing the rest of the Hellenic race taking sides with one state or the other, some at once, others planning to do so.

For this was the greatest movement that had ever stirred the Hellenes, extending also to some of the Barbarians, one might say even to a very large part of mankind.

Indeed, as to the events of the period just preceding this, and those of a still earlier date, it was impossible to get clear information on account of lapse of time; but from evidence which, on pushing my inquiries to the furthest point, I find that I can trust, I think that they were not really great either as regards the wars then waged or in other particulars.