History of the Peloponnesian War

After the treaty, and the alliance between the Lacedaemonians and Athenians, which were concluded at the end of the ten years' war, in the ephoralty of Pleistolas at Lacedaemon, and the archonship of Alcaeus at Athens, those who had acceded to them were at peace; but the Corinthians, and some of the states in the Peloponnese, were trying to alter what had been done; and another disturbance immediately arose on the part of the allies against Lacedaemon.

Moreover, the Lacedaemonians, as time went on, became suspected by the Athenians also, through not performing in some respects what had been agreed on, according to the treaty.

And though for six years and ten months they abstained from marching against each other's territory, yet out of it, during the existence of a doubtful suspension of arms, they were doing one another the greatest possible damage. Subsequently, however, they were compelled to break the treaty concluded after the ten years' war, and again proceeded to open hostilities.