Peace of Antalcidas
The Peace of Antalcidas also known as "the King's Peace" was a compromise settlement by the King of Persia to end the war between Sparta and Persia and also Athens and Sparta since Athens had come to the aid of Persia. It acknowledged the partial recovery of Athens after its devastating loss in the Second Peloponnesian War and also acknowlegded Sparta's continued hegemony. The Greek city states even agreed to nominal Persian suzerainty over Greece in the hope this would reduce jealousy among the city states and remove the internal Greek conflict that had become an ongoing part of Greek history.
Encyclopedia of Military History, Dupuy & Dupuy, 1979