The Battle of Leuctra, where Epaminondas defeated Cleombrotus I, takes place

The Battle of Leuctra (Greek: Λεῦκτρα, Ancient Greek: [lêu̯k.tra]) was a battle fought on 6 July 371 BC between the Boeotians led by the Thebans, and the Spartans along with their allies amidst the post-Corinthian War conflict. The battle took place in the neighbourhood of Leuctra, a village in Boeotia in the territory of Thespiae. The Theban victory shattered Sparta's immense influence over the Greek peninsula, which Sparta had gained with its victory in the Peloponnesian War a generation earlier.