Peace of Antalcidas
Mantineia had been a member of the Peloponnesian League, but during the Peloponnesian War, the city joined Athens. After the war, it was forced to rejoin the Peloponnese. Later, Sparta used the Peace of Antalcidas (387 BC) as a pretext to break Mantineia into its constituent villages. In response, the Mantineans expelled pro-Spartans from the city, but were vanquished in the Siege of Mantinea (385 BC), and the city was dismembered and destroyed. After the Spartan defeat at the end of the Corinthian War, Mantineia re-formed into a single city. The fortifications now became almost circular, keeping some parts of the old walls.