History of the Peloponnesian War

During this interval the Athenians were carrying in their property; and it was the belief of the Peloponnesians that a quick advance would have found everything still out, had it not been for his procrastination.

Such was the feeling of the army towards Archidamus during the siege. But he, it is said, expected that the Athenians would shrink from letting their land be wasted, and would make their submission while it was still uninjured; and this was why he waited.

But after he had assaulted Oenoe, and every possible attempt to take it had failed, as no herald came from Athens, he at last broke up his camp and invaded Attica. This was about eighty days after the Theban attempt upon Plataea, just in the middle of summer, when the corn was ripe, and Archidamus, son of Zeuxis, King of Lacedaemon, was in command.

Encamping in Eleusis and the Thriasian plain, they began their ravages, and putting to flight some Athenian horse at a place called Rheiti, or the Brooks, they then advanced, keeping Mount Aegaleus on their right, through Cropia, until they reached Acharnae, the largest of the Athenian demes or townships. Sitting down before it, they formed a camp there, and continued their ravages for a long while.

The reason why Archidamus remained in order of battle at Acharnae during this incursion, instead of descending into the plain, is said to have been this.