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.

At the same time, too, the Lacedaemonians, as time went on, incurred the suspicion of the Athenians, by not acting in some matters in accordance with the articles of the agreement.

For six years and ten months the two powers abstained from invading each other's territory; in other regions, however, there was only an unstable cessation of arms and they kept on doing each other the greatest possible damage. But at last they were forced to break the treaty which had been concluded after the first ten years, and again engaged in open war.