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.
A fight ensued, in which the Cytherians stood their ground for some little time, then turned and fled to the upper town, but afterwards capitulated to Nicias and his colleagues, agreeing to leave the question of their own fate, except as to a penalty of death, to the arbitration of the Athenians.
Some negotiations between Nicias and certain of the Cytherians had already taken place, and for this reason the settlement of the terms, both for the present and the future, was arranged more speedily and with better advantage to them;
for otherwise the Athenians would have expelled the inhabitants, since they were Lacedaemonians and the island lay in that position on the coast of Laconia. After the capitulation the Athenians took possession of Scandeia, the town at the harbour, and having taken precautions for guarding Cythera, then sailed to Asine, Helus, and most of the other towns on the seacoast; here they made raids or bivouacked at whatever place they found convenient, and ravaged the land for about seven days.
The Lacedaemonians, though they saw the Athenians in possession of Cythera and expected them to make such descents upon their own territory, nowhere massed their forces to oppose them, but sent garrisons here and there throughout the country, determining the number of hoplites by the strength needed at each point, and otherwise were very watchful, fearing lest some revolution should take place which would affect their constitution; for the calamity which had befallen them at the island of Sphacteria had been great and unexpected, Pylos and Cythera were occupied, and on all sides they were encompassed by a war which moved with a swiftness which defied precaution.
Consequently they organized, contrary to their custom, a force of four hundred cavalry and bowmen, and in military matters they now became more timid than at any time before they were involved in a naval struggle which was outside their own existing scheme of military organisation, and that too against Athenians, with whom an attempt foregone was always so much lost of what they had reckoned on accomplishing.[*](cf. 1.70.7.)
Besides, the reverses of fortune, which had befallen them unexpectedly in such numbers and in so short a time, caused very great consternation, and they were afraid that some time a calamity might again come upon them like that which had happened on the island;