Book excerpt: This book examines how the practice of episcopacy in the Church of England and the EKD affects the claim that the 'historic episcopate' is a necessary condition for 'the full interchangeability of ministers'. It addresses four questions relating to the practice of oversight: How have different forms of oversight sought to maintain the apostolic 'historic' faith in history and today? How does the exercise of authority within contemporary societies relate to the pre-modern ideas expressed in the idea of historic episcopate? How has the practice of oversight changed in the light of demographic changes and declining levels of church membership? What are the implications of synodical government and shared oversight for the concept of 'historic episcopate'? The book's goal is to explore whether an interdisciplinary analysis of episcopacy can assist the churches in establishing a new understanding of the "historic episcopate". With papers by Mark Chapman, Jonathan Gibbs, Matthias Grebe, Miriam Haar, Alex Hughes, Frances Knight, Morwenna Ludlow, Ralf Meister, Friederike Nüssel, Bernd Oberdorfer and Peter Scherle.