This book discusses the major issues currently affecting the accountability of executive power in Europe. The work is divided into three parts. The first examines the territorial dimension including unitary, regional and federal. It discusses how territorial actors participate in strengthening or weakening the implementation of accountability of executive power in modern democratic States. The second part explores the links between national traditions and European accountability of executive power to establish a common European culture. The third and final part focuses on how to build a truly multidisciplinary approach to accountability of executive power and draws on legal, historical and political approaches. The volume will be an invaluable resource for researchers, academics and policy-makers in constitutional law and politics, public law, comparative law, legal history and government.