This book explores the dynamics of health system decentralization and recentralization, investigating why and how the territorial organization of health systems changes or remains stable over time. Drawing from historical and discursive institutionalism, the explanatory framework revolves around the role of ideas, discourse and institutions. Through the analysis of the Italian and Danish health systems, the book corroborates the value of combining ideational and institutional accounts in explaining institutional continuity and change, offering new empirical and theoretical insights into the study of public policy making. The book will be of use to students and scholars interested in health politics and policy, federalism and decentralization, and theories of institutional change.