The contributions in this volume investigate interconnected aspects of the democratic deficit in global constitutionalism.The commonly shared question is the following: to what extent, if any, a global (or cosmopolitan) shift of international law can proceed absent a transnational democratic check? Some scholars are convinced that this is a real problem since that a ‘division of labour’ is to be recognized between national and regional/international legal levels, only the first needing a democratic legitimacy. The contributors to this volume, on the contrary tend to share the view that detaching the production of international law from constituent will, as well as from a democratic framework, can indeed undermine constitutional legitimacy. Furthermore, this may open the way to forms of domination that affect also state’s democratic institutions from within.What is the way out from this deadlock? How is it possible to tame global constitutionalism in order to avoid a global Leviathan? The collection of essays here presented attempts to conceptualize some of the central challenges affecting contemporary patterns of legal dispersion and fragmentation. They follow a conceptual-historical thread which starts with a modern Kantian understanding of the problem, and unfolds into the discussion of issues of constitutional pluralism, institutional legitimacy and the risk of tyranny. The volume includes analyses of the role of China and the EU, two of the most important actors, even though perhaps at the opposite pole of the global constitutional project.