Following the end of the Peloponnesian War, various poleis of Greece vied for power -- especially Sparta, Athens, and Thebes.
The Corinthian War was fought between 395 and 386 B.C. by Sparta, leading the Peloponnesian forces, on the one side, and an alliance of Thebes and Corinth -- former allies of Sparta, Athens, and Argos on the other.
Persia, in response to King Agesilaus-led Sparta's antagonizing the Persian king, Artaxerxes II, helped Athens with fleet-building, at first. Then, when Athens gained power, Persia switched sides.
Sparta defeated the coalition at the Battle of Nemea in 394. Afterwards, fighting centered around Corinthian territory, for which reason the war is called the Corinthian War. Athens won a sea battle at Cnidus in 394, under Conon.
The Persians then helped the Spartans, with the collapse of the coalition, loss of the Athenian empire, and increased power for Sparta, as results.
In 386, the war ended with Persian intervention known as The King's Peace named for the agreement Artaxerxes reached with the Greeks to leave them alone in exchange for their recognizing that Cyrus and cities in Asia belonged to him. or Peace of Antalcidas, named for a Spartan involved in the negotiations.
In the 370s there was frequent fighting, with Thebes in the ascendant. Thebes defeated Sparta at Leuctra, in 371. Then in 370, Thebes marched on the Peloponnese under General Epaminondas. Thebes was doing well, but its very success meant it had more territory to control than it was capable of.
Ultimately. Athens allied with Sparta to defeat Thebes.
Sources:
- John Lazenby "Greek city-state wars" The Oxford Companion to Military History. Ed. Richard Holmes. Oxford University Press, 2001.
- James M. Williams "Corinthian War" The Oxford Encyclopedia of Ancient Greece and Rome. Ed. Michael Gagarin. © Oxford University Press 2010.
- "King's Peace" Oxford Dictionary of the Classical World. Ed. John Roberts. © Oxford University Press 2000, 2004, 2007.

