This insightful book discusses the impact of EU law on the creation and empowerment of autonomous public bodies (APBs) at Member State level and analyzes recent attempts of European states to rationalize delegation to APBs. It examines the tensions between these trends: under what conditions can APBs be considered legitimate forms of government in the light of modern conceptions of constitutionalism, the rule of law and democracy - values that are deeply rooted in European constitutions? And to what extent do EU obligations on the independence of national regulators, data protection authorities and the like conflict with those conceptions?