The battle of Leuctra, fought between the forces of Sparta and the Boeotian League led by Thebes, in early July 371 BC, altered forever the map of ancient Greek history. In a single afternoon, what the ancient Greeks of the early 4th century BC had come to understand as their world order was swept way. The Theban tactics at Leuctra included the revolutionary ideas of deployment in depth and of a refused flank, where part of a formation was drawn up in echelon.