Thucydides, History of the Peloponnesian War
Benjamin Jowett, Ed.

35. During this summer the Dictidians took Thyssus, a town of Mount Athos, which was in alliance¹ with the Athenians. [2] During the whole summer intercourse continued between the Athenians and Peloponnesians. But almost as soon as the peace was concluded both Athenians and Lacedaemonians began to mistrust one another, because the places mentioned in the treaty were not given up. [3] For the Lacedaemonians, who were to make restitution first, according to the lot, had not surrendered Amphipolis and the other less important places which they held, and had not made their allies in Chalcidicè, nor the Boeotians, nor the Corinthians accept the treaty, but only kept declaring that they would join the Athenians in coercing them if they continued to refuse. They even fixed a time, though they did not commit themselves in writing, within which those who would not come into the treaty were to be declared the enemies of both parties. [4] The Athenians, seeing that nothing was being really done, suspected the Lacedaemonians of dishonesty, and therefore they would not give up Pylos when the Lacedaemonians required it; [5] they even repented that they had restored the prisoners taken at Sphacteria, and resolved to keep the other places until the Lacedaemonians had fulfilled their part of the contract. The Lacedaemonians replied that they had done what they could. They had delivered up the Athenian prisoners who were in their hands, and had withdrawn their soldiers from Chalcidicè; they had neglected nothing which lay within their power. But they could not give up Amphipolis, of which they were not entirely masters; [6] they would however try to bring the Boeotians and Corinthians into the treaty, to get back Panactum, and recover all the Athenian captives who were in the hands of the Boeotians. [7] They still continued to insist on the restoration of Pylos, or at any rate on the withdrawal of the Messenians and Helots, now that the Lacedaemonians had withdrawn their troops from Chalcidicè; the Athenians might, if they liked, garrison the place themselves. After many long conferences held during the summer, they persuaded the Athenians to withdraw the Messenians, Helots, and Lacedaemonian deserters: these the Athenians settled at Cranii in Cephallenia. [8] So during this summer there was peace and intercourse between Athens and Sparta.