 But Sparta, jealous of the increasing prosperity of its ally, availed itself of the first pretext to pick a quarrel.At the Battle of Mantinea (418 BC), the Eleans fought against the Spartans, who later took vengeance upon them by depriving them of Triphylia and the towns of the Acrorea.The Eleans made no attempt to re-establish their authority over these places until Thebes rose in importance after the Battle of Leuctra (371 BC).