About 180 city-states of Asia Minor and the Aegean islandscalled the Delian league, which ad been led by Athens against thePersian Empire, were converted into an empire of Athens after thePersian threat ended. Athens lived of the resources of thesecities, and levied naval and land forces from them. This gave itthe power to meddle in the affairs of other Greek city-states,leading to the devastating 27-year Peloponnesian War against thePeloponnesian League led by Sparta.