Beginning of Peloponnesian War

The triumphs and the power of Athens were regarded with fear and jealousy by her rivals; and the quarrel between Corinth and Corcyra lighted the spark which was to produce the conflagration. On the coast of Illyria near the site of the modern Durazzo, the Corcyraeans had founded the city of Epidamnus. Corcyra (now Corfu) was itself a colony of Corinth; and though long at enmity with its mother country, was forced, according to the time- hallowed custom of the Greeks in such matters, to select the founder of Epidamnus from the Corinthians. Accordingly Corinth became the metropolis of Epidamnus as well as of Corcyra. At the time of which we speak, the Epidamnians, being hard pressed by the Illyrians, led by some oligarchical exiles of their own city, applied to Corcyra for assistance, which the Corcyraeans, being connected with the Epidamnian oligarchy, refused. The Epidamnians then sought help from the Corinthians, who undertook to assist them. The Corcyraeans, highly resenting this interference, attacked the Corinthian fleet off Cape Actium, and gained a signal victory (B.C. 435).

Deeply humbled by this defeat, the Corinthians spent the two following years in active preparations for retrieving it. The Corcyraeans, who had not enrolled themselves either in the Lacedaemonian or Athenian alliance, and therefore stood alone, were greatly alarmed at these preparations. They now resolved to remedy this deficiency; and as Corinth belonged to the Lacedaemonian alliance, the Corcyraeans had no option, and were obliged to apply to Athens. The majority of the Athenians were ready to comply with their request; but in order to avoid an open infringement of the Thirty Years' Truce, it was resolved to conclude only a defensive alliance with Corcyra: that is, to defend the Corcyraeans in case their territories were actually invaded by the Corinthians, but beyond that not to lend them any active assistance. A small Athenian squadron of only 10 triremes was despatched to the assistance of the Corcyraeans. Soon after their arrival a battle ensued off the coast of Epirus, between the Corinthian and Corcyraean fleets. After a hard-fought day, victory finally declared in favour of the Corinthians. The Athenians now abandoned their neutrality, and did all in their power to save the dying Corcyraeans from their pursuers. This action took place early in the morning; and the Corinthians prepared to renew the attack in the afternoon, when they saw in the distance 20 Athenian vessels, which they believed to be the advanced guard of a still larger fleet. They accordingly sailed away to the coast of Epirus; but finding that the Athenians did not mean to undertake offensive operations against them, they departed homewards with their whole fleet. These events took place in the year B.C. 432.

William Smith, A Smaller History of Ancient Greece

From the end of the Persian Wars to the beginning of the Peloponnesian War, B.C. 479-431

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