The Pythaïs procession is an Athenian feast with several peculiarities: Contrary to most other Athenian processions it did not take place periodically but irregularly and overall rather seldom. The procession, however, was of great political importance as it was meant to underline the leading position of Athens and the connection between Athens and the Pan Hellenic sanctuary in Delphi. In this publication all available epigraphic, literary and archaeological sources are brought together and being evaluated anew, above all the extraordinarily rich inscriptions of Hellenistic times and the Roman imperial era which is being presented here in a complete translation for the first time. In addition to the analysis and the comparison of the changing groups of participants, especially in Hellenistic times, the reconstruction of the unusually long way from Athens to Delphi is being focused. Thus this volume offers a comprehensive reconstruction of the Pythaïs ritual.