History of the Peloponnesian War

The same winter the Ambraciotes, according to their promise made to Eurylochus when they retained his army, made war upon Argos in Amphilochia with three thousand men of arms, and invading Argeia, they took Olpae, a strong fort on a hill by the sea-side, which the Acarnanians had fortified and used for the place of their common meetings for matters of justice, and is distant from the city of Argos, which stands also on the sea-side, about twenty-five furlongs.

The Acarnanians, with part of their forces, came to relieve Argos; and with the rest they encamped in that part of Amphilochia which is called Crenae to watch the Peloponnesians that were with Eurylochus that they might not pass through to the Ambraciotes without their knowledge;

and sent to Demosthenes, who had been leader of the Athenians in the expedition against the Aetolians, to come to them and be their general. They sent also to the twenty Athenian galleys that chanced to be then on the coast of Peloponnesus under the conduct of Aristoteles, the son of Timocrates, and Hierophon, the son of Antimnestus.

In like manner the Ambraciotes that were at Olpae sent a messenger to the city of Ambracia, willing them to come to their aid with their whole power, as fearing that those with Eurylochus would not be able to pass by the Acarnanians, and so they should be either forced to fight alone or else have an unsafe retreat.