The League of Corinth was established as a common peace agreement by Philip II of Macedonia after the Battle of Chaeronea. Its terms included the autonomy of the member city-states but also some military obligations on their part. Philip II was the official leader of the League.
Bouchard, Elsa. "Establishment of the League of Corinth". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11278, accessed 30 September 2014.]