History of the Peloponnesian War

The same winter the Ambraciots, as they had promised Eurylochus when they retained his army, marched out against Amphilochian Argos with three thousand heavy infantry, and invading the Argive territory occupied Olpae, a stronghold on a hill near the sea, which had been formerly fortified by the Acarnanians and used as the place of assizes for their nation, and which is about two miles and three-quarters from the city of Argos upon the sea-coast.

Meanwhile the Acarnanians went with a part of their forces to the relief of Argos, and with the rest encamped in Amphilochia at the place called Krenae, or the Wells, to watch for Eurylochus and his Peloponnesians, and to prevent their passing through and effecting their junction with the Ambraciots;

while they also sent for Demosthenes, the commander of the Aetolian expedition, to be their leader, and for the twenty Athenian ships that were cruising off Peloponnese under the command of Aristotle, son of Timocrates, and Hierophon, son of Antimnestus.

On their part, the Ambraciots at Olpae sent a messenger to their own city, to beg them to come with their whole levy to their assistance, fearing that the army of Eurylochus might not be able to pass through the Acarnanians, and that they might themselves be obliged to fight single-handed, or be unable to retreat, if they wished it, without danger.