Peace of Antalcidas
After Sparta's defeat in 371 BC, Thebes seceded from the League and was able to violate the terms of the Peace of Antalcidas with impunity. Later, a series of revolts rocked the league, culminating with the Social War (357–355 BC) in which the states of Chios, Rhodes, Kos, and Byzantium went to war against Athens. This war ended in the disintegration of the Second Athenian League.