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.
Citation:
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 19 June 2013.]