The 1st Sacred War, which should be placed at the start of the 6th century B.C., if we accept the piece of information that Solon also took part in it - traditionally originated initially in the piratical assaults of the inhabitants of Cirrha on worshippers making their way to Delphi. The Amphictyonic Council decided to punish the people of Cirrha. In charge of the attack were two Thessalians, Eurylochus and Hippias. The Athenians sent a body under the leadership of Alcmaeon, while Cleisthenes tyrant of Sicyon blockaded the city from the sea, for which he was rewarded with a third of the spoils. Cirrha finally fell, and its inhabitants were sold into slavery. Cultivation of the city's lands was prohibited and it was decided that they should be consecrated to Apollo, Artemis, Leto and Athena Pronaea and should be given over to the pasturage of the sacrificial animals. The people of Cirrha took refuge on the heights of Cirphe, and the last seedbeds of resistance were eliminated within five years.

At the end of the 7th century B.C., by intervening in colonization, the Oracle of Delphi had won such a reputation that certain cities and coalitions felt justified in trying to bring it under their control. It was contended that before the War the oracle had been under Dorian control. The 1st Sacred War and the consequent restructuring of the Delphic-Pylaean Amphictyony resulted in Delphi becoming established as the privileged meeting-place for adversaries in wartime. Moreover, as archaeological finds prove, throughout the 6th century, the presence of Athens and other Ionian cities at Delphi was become more marked. It is now that the Pythian Games, originally confined to musical contests, take on Panhellenic significance.