History of the Peloponnesian War

When the army was assembled at Delphi, Eurylochus sent a herald to the Locrians of Ozolae both because their way lay through them to Naupactus, and also because he desired to make them revolt from the Athenians.

Of all the Locrians the Amphissians co-operated with him most, as standing most in fear for the enmity of the Phoceans. And they first giving hostages induced others who likewise were afraid of the coming in of the army to do the like: the Myoneans first, being their neighbours, for this way is Locris of most difficult access; then the Ipneans, Messapians, Tritaeans, Chalaeans, Tolophonians, Hessians, and the Oeantheans. All these went with them to the war. The Olpaeans gave them hostages but followed not the army. But the Hyaeans would give them no hostages till they had taken a village of theirs called Polis.

When everything was ready and he had sent the hostages away to Cytinium in Doris, he marched with his army towards Naupactus through the territory of the Locrians. And as he marched, he took Oeneon, a town of theirs, and Eupalium because they refused to yield unto him.