The Corinthian War (395–387 BC) was a conflict in ancient Greece which pitted Sparta against a coalition of city-states comprising Thebes, Athens, Corinth and Argos, backed by the Achaemenid Empire. The war was caused by dissatisfaction with Spartan imperialism in the aftermath of the Peloponnesian War (431–404 BC), both from Athens, the defeated side in that conflict, and from Sparta's former allies, Corinth and Thebes, who had not been properly rewarded. Taking advantage of the fact that the Spartan king Agesilaus II was away campaigning in Asia against the Achaemenid Empire, Thebes, Athens, Corinth and Argos forged an alliance in 395 BC with the goal of ending Spartan hegemony over Greece; the allies' war council was located in Corinth, which gave its name to the war. By the end of the conflict, the allies had failed to end Spartan hegemony over Greece, although Sparta was weakened by the war.
At first, the Spartans achieved several successes in pitched battles (at Nemea and Coroneia), but lost their advantage after their fleet was destroyed at the naval Battle of Cnidus against the Persian fleet, which effectively ended Sparta's attempts to become a naval power. As a result, Athens launched several naval campaigns in the later years of the war, recapturing a number of islands that had been part of the original Delian League during the 5th century BC. Alarmed by these Athenian successes, the Persians stopped backing the allies and began supporting Sparta. This defection forced the allies to seek peace.
