Battle of Leuctra
Theban authority grew so spectacularly in such a short time that Athens came to mistrust the growing Theban power. Athens began to consolidate its position again through the formation of a second Athenian League. Attention was drawn to growing power of Thebes when it began interfering in the political affairs of its neighbor, Phocis, and, particularly, after Thebes razed the city of Plataea, a long-standing ally of Athens, in 375 BC. The destruction of Plataea caused Athens to negotiate an alliance with Sparta against Thebes, in that same year. In 371, the Theban army, led by Epaminondas, inflicted a bloody defeat on Spartan forces at Battle of Leuctra. Sparta lost a large part of its army and 400 of its 2,000 citizen-troops. The Battle of Leuctra was a watershed in Greek history. Epaminondas' victory ended a long history of Spartan military prestige and dominance over Greece and the period of Spartan hegemony was over. However, Spartan hegemony was not replaced by Theban, but rather by Athenian hegemony.