The Delian League, founded in 478 BC, was an association of Greek city-states, numbering between 150 and 330, under the leadership of Athens, whose purpose was to continue fighting the Persian Empire after the Greek victory in the Battle of Plataea at the end of the Second Persian invasion of Greece. The League's modern name derives from its official meeting place, the island of Delos, where congresses were held in the temple and where the treasury stood until, in a symbolic gesture, Pericles moved it to Athens in 454 BC.