This book pursues the research question of how power was justified in fifteenth- and early sixteenth-century Europe. It addresses the arguments that people at the time found convincing. The main focus is on the period from the beginning of the fifteenth century until the eve of the Reformation, although these edges are of necessity fuzzy, especially because material from an earlier period often has to be included. It takes the story of power on from my last book and seeks to develop a more nuanced treatment of ideas of legitimate power and authority.1