Important Greek sanctuaries such as Delphi were traditionally managed by religious leagues (called Amphictionies) that included representatives from both local and outside cities. The Second Sacred War was launched when Sparta sought to restore Amphictionic power at Delphi after Athens had placed the sanctuary under the control of its Phocian allies. The enterprise was temporarily successful but Athens soon gave back to the Phocians the authority over Delphi.
Bouchard, Elsa. "Second Sacred War". The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=11212, accessed 31 July 2014.]