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.
Many of the allies were slain, and of the Athenians themselves about one hundred and twenty hoplites. So great a number of men, and all of the same age, perished here, the best men in truth whom the city of Athens lost in this war; and Procles, one of the two generals, perished also.
When they had received back their dead from the Aetolians under a truce and had retreated to Naupactus, they were afterwards taken back by the fleet to Athens. Demosthenes, however, remained behind in Naupactus and the region round about, for he was afraid of the Athenians because of what had happened.
About the same time the Athenian forces over in Sicily sailed to Locris[*](ie. the territory of the Epizephyrian Locri, north of Rhegium in Italy.) and disembarking there defeated the Locrians who came against them and took a guard-house which was situated on the river Halex.
During the same summer the Aetolians, who had previously sent three envoys to Corinth and Lacedaemon, namely Tolophus the Ophionean, Boriades the Eurytanian, and Teisander the Apodotian, urged them to send an army against Naupactus because this city had brought the Athenians against them.
So towards autumn the Lacedaemonians sent three thousand hoplites of their allies, among whom were six hundred from Heracleia, the city which had recently been founded in Trachis. The commander of the expedition was Eurylochus a Spartan, who was accompanied by the Spartans Macarius and Menedaïus.
And when the army was collected at Delphi, Eurylochus sent a herald to the Ozolian Locrians; for the road to Naupactus lay through their territory, and he also wished to induce them to revolt from Athens.
Of the Locrians the people of Amphissa co-operated with him chiefly, these being afraid on account of their enmity to the Phocians; and after these had taken the lead in giving him hostages they persuaded the rest, who were afraid of the invading army, to do likewise—first their neighbours the Myoneans, who held the country from which Locris was most difficult of access, then the Ipneans, Messapians, Tritaeeans, Chalaeans, Tolophonians, Hessians and Oeantheans. All these tribes also took part in the expedition. The Olpaeans gave hostages, but did not take the field with the others; and the Hyaeans refused to give hostages until a village of theirs, Polis by name, was taken.