History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
After pitching their camp there, they first ravaged Eleusis and the Thriasian plain, and put to flight some Athenian cavalry near a place called Rheiti [or
the brooks]. Afterwards they continued their march, keeping Mount Aegaleos on their right through Cropaea, till they came to Acharnae, a place which is the largest of the demes, [or townships,] as they are called, of Attica. And sitting down before it they formed an encampment, and stayed a long time in the place, and continued ravaging it.
It was with the following views that Archidamus is said to have remained in order of battle at Acharnae, and not to have gone down to the plain during that incursion.
He hoped that the Athenians, abounding as they were in numbers of young men, and prepared for war as they had never before been, would perhaps come out against him, and not stand still and see their land ravaged.
Since, then, they had not met him at Eleusis and the Thriasian plain, he pitched his camp at Acharnae, and tried whether they would now march out against him.
For he thought the post a favourable one for encamping in, and moreover that the Acharnians, forming as they did a large part of the state, (for they amounted to three thousand heavy-armed,) would not overlook the destruction of what belonged to them, but would stir up the whole army also to an engagement. If, on the other hand, the Athenians should not come out against him during that incursion, he would then lay waste the plain with less fear in future, and advance to the city itself; for the Acharnians, after losing their own property, would not be so forward to run into danger for that of other people, but there would be a division in their counsels.
It was with this view of the case that Archidamus remained at Acharnae.
As for the Athenians, so long as the army was in the neighbourhood of Eleusis and the Thriasian plain, they had some hope of its not advancing nearer; remembering the case of Pleistoanax, the son of Pausanias, the king of the Lacedaemonians, when with a Peloponnesian army he made an inroad into Attica, as far as Eleusis and Thria, fourteen years before this war, and retired again without advancing any further (for which reason indeed he was banished from Sparta, as he was thought to have been bribed to make the retreat).
When, however, they saw the army at Acharnae, only sixty stades from the city, they considered it no longer bearable, and, as was natural, when their land was being ravaged before their eyes—a thing which the younger men had never yet seen, nor even the elder, except in the Persian wars—it was thought a great indignity, and all of them, especially the young men, determined to go out against them, and not to put up with it.