Delian League (former group of nations/states/cities)
Note: Association of 150 to 173 Greek city-states that existed ca. 477-404 BCE under the leadership of Athens. The purpose of the league was to continue fighting the Persian Empire after the Greek victory in the Battle of Plataea at the end of the Greco-Persian Wars. The official meeting place was the island of Delos, where congresses were held in the temple and where the treasury stood until Pericles moved it to Athens in 454 BCE.