This comprehensive collection offers a concise introduction to the institutional framework of the Holy See, conceptualizing papal agency and positions from a range of international theory perspectives. The authors – international scholars from political science, history, and religious studies – explore multiple fields of papal and Vatican influence, ranging from spy networks and inter-religious dialogue to social doctrine and religious freedom.This book demonstrates that, contrary to secularization theory, the papacy is not in decline in world politics. Since World War II, the Holy See has played a steadily increasing role in international relations. Globalization supports the role of the Catholic Church as a transnational actor not only in the advanced industrial societies of the West but also increasingly across the Global South. In this volume, the authors document the legacies of John Paul II and Benedict XVI as well as the current pontificate of Pope Francis from a range of contemporary perspectives.This book comprises research articles and commentary essays on the papacy in world politics originally published in The Review of Faith & International Affairs.