Peace of Nicias
In 449-448 the Phocians, wanting to become masters of the sanctuary, marched against Delphi, but the Spartans sent an army and restored things, thus causing the second Sacred War. After the Spartans’ departure, the Athenians, led by Pericles, gave back to the Phocians the rule of Delphi and the management of the Pythian Games. In 421, after the Peace of Nicias, Delphi became autonomous again. It is unlikely, however, that Phocis remained in control of Delphi after members of the Boeotian League defeated Athens at the Battle of Coronea (447 BCE).