High Quality Content by WIKIPEDIA articles! The Battle of Mantinea was fought on July 4 362 BC between the Thebans, led by Epaminondas and supported by the Arcadians and the Boeotian league against the Spartans, led by King Agesilaus II and supported by the Eleans, Athenians, and Mantineans. The battle was to decide the hegemony over Greece, but the death of Epaminondas and the defeat of the Spartans paved the way for Macedonian conquest by Phillip II of Macedon.