Battle of Mantinea
In 367 BC, during Epaminondas’ third invasion of the Peloponnese, the Achaean cities agreed to an alliance with Thebes. But soon when oligarchs retook the cities of Achaea they allied with Sparta against Epaminondas. At the Battle of Mantinea in 362 BC the Achaeans were allied to Sparta, Athens and Mantinea against Thebes.