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.
And in every way they made haste that they might complete the fortification of the most vulnerable points before the Lacedaemonians came out against them; for the greater part of the place was so strong by nature that it had no need of a wall.
As for the Lacedaemonians, they happened to be celebrating a festival when they got word of the undertaking, and made light of it, thinking that the Athenians would not await their attack when they got ready to take the field, or, if they should, that they could easily take the place by force;
and the fact also that their army was still in Attica had something to do with their delay. The Athenians in six days completed the wall on the side toward the land and at such other points as most needed it, and left Demosthenes there with five ships to defend it; they then took the main body of the fleet and hastened on their voyage to Corcyra and Sicily.
But the Peloponnesians who were in Attica, when they heard that Pylos had been occupied, returned home in haste; for King Agis and the Lacedaemonians thought that the Athenian operations at Pylos were a matter of deep concern to them. And at the same time, since they had made their invasion early in the season when the grain was still green, most of them[*](Each division had its own commissariat, and some were better provisioned than the main body. Classen explains, “were short of food for so large an army” (τοῖς πολλοῖς).) were short of food, and bad weather, which came on with storms of greater violence than was to be expected so late in the spring, distressed the army.
Consequently there were many reasons why they hastened their retirement from Attica and made this the shortest of their invasions; for they remained there only fifteen days.
About the same time Simonides, an Athenian general, getting together a few Athenians from the garrisons in Thrace and a large force from the allies in that neighbourhood, got, by the treachery of its inhabitants, possession of Eion in Thrace, a colony of the Mendaeans and hostile to Athens. But succour came promptly from the Chalcidians and the Bottiaeans and he was driven out with the loss of many of his soldiers.
On the return of the Peloponnesians from Attica, the Spartans themselves and the Perioeci who were in the neighbourhood of Pylos at once came to its relief; but the other Lacedaemonians were slower in coming, since they had just got back from another campaign.
Word was also sent round to the states of the Peloponnesus, summoning them to come to the relief of Pylos as quickly as possible, and also to the sixty ships that were at Corcyra.[*](cf. 4.2.3.) These were hauled across the Leucadian isthmus, and without being discovered by the Attic ships, which were now at Zacynthus, reached Pylos, where their land forces had already arrived.