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.
indeed his army had no sooner invaded their country than they all began to rally in great force, so that help came even from the remotest tribes of the Ophioneans, who stretch as far as the Maliac Gulf, and from the Bomians and Callians.
The Messenians, however, gave Demosthenes about the same advice as at first: informing him that the conquest of the Aetolians was easy, they urged him to proceed as quickly as possible against the villages, not waiting until they should all unite and array themselves against him, but trying to take the first village in his way.
Yielding to their advice and being hopeful because of his good fortune, since he was meeting with no opposition, he did not wait for the Locrians, who were to have brought him reinforcements—for he was greatly in need of lightarmed men that were javelin-throwers—but advanced against Aegitium and took it by storm at the first onset. For the inhabitants secretly fled and took post on the hills above the city, which stood on high ground about eighty stadia from the sea.
But the Aetolians, who by this time had come to the rescue of Aegitium, attacked the Athenians and their allies, running down from the hills on every side and showering javelins upon them, then retreating whenever the Athenian army advanced and advancing whenever they retreated. Indeed, the battle continued for a long time in this fashion, alternate pursuits and retreats, and in both the Athenians had the worst of it.
Now so long as their bowmen had arrows and were able to use them the Athenians held out, for the Aetolian troops were light-armed and so, while they were exposed to the arrows, they were constantly driven back. But when the captain of the archers had been killed and his men scattered, and the hoplites were worn out, since they had been engaged for a long time in the unremitting struggle and the Aetolians were pressing them hard and hurling javelins upon them, they at last turned and fled, and falling into ravines from which there was no way out and into places with which they were unacquainted, they perished;