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.
After this the Athenians, marching to Plataea, brought in food and left a garrison,[*](cf. 78.3.) taking away the least efficient of the men along with the women and children.
Now that the affair at Plataea had occurred and the treaty had been glaringly violated, the Athenians began preparing for war, and the Lacedaemonians and their allies also began; both sides were making ready to send embassies to the King and to the barbarians of any other land,[*](Referring in the one case, to the unsuccessful embassy of the Lacedaemonians to the King mentioned in 67; in the other, to the connection of the Athenians with the Odrysian court mentioned in 2.29 and 2.67.) where either of them hoped to secure aid, and they were negotiating alliances with such cities as were outside of their own sphere of influence.
The Lacedaemonians, on their part, gave orders to those in Italy and Sicily who had chosen their side[*](Referring to the Dorian colonies in Italy and Sicily (cf. 3.86.2), which, however, contributed no ships till 412 B.C. (cf. 8.26.1.) to build, in proportion to the size of their cities, other ships, in addition to those which were already in Peloponnesian ports, their hope being that their fleet would reach a grand total of five hundred ships, and to provide a stated sum of money; but as to other matters, they were instructed to remain inactive and to refuse their ports to Athenians if they came with more than a single ship, until these preparations had been completed.