In 431 B.C. Corcyra (Corfu), a colony of Corinth, rebelled against its metropolis. Athens, wanting to use the fleet of Corcyra, placed the island under its aegis and admitted it to the Delian League. This episode provoked a long and bloody war, the Peloponnesian War, of which Athens and its rival, Sparta, were the protagonists. Athens had planned to turn this conflict into a war at sea but even there some of its efforts were unsuccessful. In addition plague afflicted the people of Athens. Sparta, on the other hand, was unable to wage a sea war and starve Athens by blockading it from the sea. The two sides agreed to a fifty-year truce (The Peace of Nikias) in a war that seemed to give no one the upper hand. With the Peace of Nikias both sides agreed to return all conquered lands. The Athenians were unhappy with the outcome of this first phase of the war. Alkibiades, who became prominent in Athenian politics after the death of Pericles, convinced the Athenians that they should bring the Greeks of Sicily on their side. His subsequent military campaign in Italy to achieve this objective met with disaster when the Athenian army was defeated in 413 B.C. in Sicily. This defeat gave impetus to Sparta to obtain Persian support to finish off its rival, Athens. During the last turn of this Great War, the Athenians managed a short-lived victory at Arginousae, off the island of Lesbos, but were later defeated by the Spartans at a naval battle at Aegos Potamoi. Without a fleet, Athens was totally vanquished and subjugated to Sparta. Athenian power and prosperity came to an end and Sparta, which had entered this war to ensure the autonomy of the Greek city-states from the Athenian Hegemony, had to keep this promise. But, instead of making steps towards the creation of a united Greek front, Sparta followed the example of Athens and created a Spartan Hegemony which lasted less than 25 years.