History of the Peloponnesian War

This also hath the same Thucydides of Athens written from point to point, by summers and winters, as everything came to pass, until such time as the Lacedaemonians and their confederates had made an end of the Athenian dominion and had taken their long walls and Pieraeus. To which time, from the beginning of the war, it is in all twenty-seven years.

As for the composition between, if any man shall think it not to be accounted with the war, he shall think amiss. For let him look into the actions that passed as they are distinctly set down and he shall find that that deserveth not to be taken for a peace, in which they neither rendered all nor accepted all, according to the articles. Besides, in the Mantinean and Epidaurian wars and in other actions, it was on both sides infringed; moreover, the confederates on the borders of Thrace continued in hostility as before; and the Boeotians had but a truce from one ten days to another.

So that with the first ten years' war, and with this doubtful cessation, and the war that followed after it, a man shall find, counting by the times, that it came to just so many years and some few days, and that those who built upon the prediction of the oracles have this number only to agree.