The Spartans under King Agesilaus II invade Arcadia. After appealing in vain to the Athenians for help, Arcadia turns to the Thebans. Epaminondas of Thebes arrives with an army, finds the Spartan have retired and follows them.
With the support of Thebes, the Arcadian capital city of Megalopolis is completed and a democratic system is set up with an Assembly of Ten Thousand and a Council of fifty.