When the Corcyraeans heard of their preparations they came to Corinth with envoys from Lacedaemon and Sicyon, whom they persuaded to accompany them, and bade her recall the garrison and settlers, as she had nothing to do with Epidamnus. If, however, she had any claims to make, they were willing to submit the matter to the arbitration of such of the cities in Peloponnese as should be chosen by mutual agreement, and that the colony should remain with the city to whom the arbitrators might assign it. They were also willing to refer the matter to the oracle at Delphi. If, in defiance of their protestations, war was appealed to, they should be themselves compelled by this violence to seek friends in quarters where they had no desire to seek them, and to make even old ties give way to the necessity of assistance. The answer they got from Corinth was that, if they would withdraw their fleet and the barbarians from Epidamnus, negotiation might be possible; but, while the town was still being besieged, going before arbitrators was out of the question. The Corcyraeans retorted that if Corinth would withdraw her troops from Epidamnus they would withdraw theirs, or they were ready to let both parties remain in statu quo, an armistice being concluded till judgment could be given.
Turning a deaf ear to all these proposals, when their ships were manned and their allies had come in, the Corinthians sent a herald before them to declare war and, getting under way with seventy-five ships and two thousand heavy infantry, sailed for Epidamnus to give battle to the Corcyraeans. The fleet was under the command of Aristeus, son of Pellichas, Callicrates, son of Callias, and Timanor, son of Timanthes; the troops under that of Archetimus, son of Eurytimus, and Isarchidas, son of Isarchus. When they had reached Actium in the territory of Anactorium, at the mouth of the mouth of the Gulf of Ambracia, where the temple of Apollo stands, the Corcyraeans sent on a herald in a light boat to warn them not to sail against them. Meanwhile they proceeded to man their ships, all of which had been equipped for action, the old vessels being undergirded to make them seaworthy. On the return of the herald without any peaceful answer from the Corinthians, their ships being now manned, they put out to sea to meet the enemy with a fleet of eighty sail (forty were engaged in the siege of Epidamnus), formed line, and went into action, and gained a decisive victory, and destroyed fifteen of the Corinthian vessels. The same day had seen Epidamnus compelled by its besiegers to capitulate; the conditions being that the foreigners should be sold, and the Corinthians kept as prisoners of war, till their fate should be otherwise decided.
After the engagement the Corcyraeans set up a trophy on Leukimme, a headland of Corcyra, and slew all their captives except the Corinthians, whom they kept as prisoners of war. Defeated at sea, the Corinthians and their allies repaired home, and left the Corcyraeans masters of all the sea about those parts. Sailing to Leucas, a Corinthian colony, they ravaged their territory, and burnt Cyllene, the harbour of the Eleans, because they had furnished ships and money to Corinth. For almost the whole of the period that followed the battle they remained masters of the sea, and the allies of Corinth were harassed by Corcyraean cruisers. At last Corinth, roused by the sufferings of her allies, sent out ships and troops in the fall of the summer, who formed an encampment at Actium and about Chimerium, in Thesprotis, for the protection of Leucas and the rest of the friendly cities. The Corcyraeans on their part formed a similar station on Leukimme. Neither party made any movement, but they remained confronting each other till the end of the summer, and winter was at hand before either of them returned home.
Corinth, exasperated by the war with the Corcyraeans, spent the whole of the year after the engagement and that succeeding it in building ships, and in straining every nerve to form an efficient fleet; rowers being drawn from Peloponnese and the rest of Hellas by the inducement of large bounties. The Corcyraeans, alarmed at the news of their preparations, being without a single ally in Hellas (for they had not enrolled themselves either in the Athenian or in the Lacedaemonian confederacy), decided to repair to Athens in order to enter into alliance and to endeavour to procure support from her.
Corinth also, hearing of their intentions, sent an embassy to Athens to prevent the Corcyraean navy being joined by the Athenian, and her prospect of ordering the war according to her wishes being thus impeded. An assembly was convoked, and the rival advocates appeared:
the Corcyraeans spoke as follows: