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.
For in the interval the Athenians continued to bring their property into the city and the Peloponnesians believed that but for his procrastination they could have advanced quickly and found everything still outside.
Such was the resentment felt by the army toward Archidamus while they were sitting still. But the reason, it is said, whiy he kept holding back was that he expected the Athenians would make some concession while their territory was still unravaged and would be loath to see it laid waste.
When, however, after assaulting Oenoe and trying in every way to take it they were not able to do so, the Athenians meanwhile making no overtures, then at length they set off from there, about eighty days after the events at Plataea, when it was midsummer[*](The reference is to the Attic summer, which included spring. The date was about the end of May, the average time for cutting grain in Attica.) and the corn was ripe, and invaded Attica, under the command of Arehidamus son of Zeuxidamus, king of the Lacedaemonians.
Making a halt they proceeded to ravage, first of all, the territory of Eleusis and the Thriasian plain, and they routed the Athenian cavalry near the streams called Rheiti; then they advanced, keeping Mount Aegaleos on their right through Cropia,[*](A deme between Aegaleos and Parnes.) until they came to Acharnae, the largest of the demes of Attica, as they are called. Halting in the town they made a camp, where they remained for a long time ravaging the country.
And it is said that the motive of Archidamus in waiting about Acharnae with his troops ready for battle, instead of descending into the plain during this invasion, was as follows:
He cherished the hope that the Athenians, who were at their very best as regards the multitude of their youth and prepared for war as never before, would perhaps come out against him and not look on and see their land ravaged.
So when they did not come to meet him at Eleusis and in the Thriasian plain, he settled down in the neighbourhood of Acharnae, to make a test whether they would come out;
for not only did that seem to him a suitable place for his camp, but also the Acharnians were an important part of the state, their hoplites numbering three thousand, and he thought that they would not look on and see their fields ravaged, but would urge the whole people also to fight. And even if the Athenians should not come out against him during this invasion, he would thenceforward proceed with less apprehension to ravage the plain and even advance to the very walls of the city; for the Acharnians, once stripped of their own possessions, would not be as eager to incur danger as before in behalf of the lands of the rest, and so a division would arise in the counsels of the Athenians.
It was with this design that Archidamus stayed at Acharnae.