Over the past thirty years, sub-State national minorities in a number of developed liberal democracies have both reasserted their cultural distinctiveness and demanded recognition of it in legal and political terms. This phenomenon has been the subject of considerable study by sociologists, political scientists, and political theorists. This book differs by offering a study of the consequences of these rights claims for legal systems. It examines the role played by law, especially constitutional law, in the negotiation of the complex relationships and competing rights claims involving the State, national minorities, and other groups and individuals within the State. This book addresses the constitutional issues, both in theory and in practice, that accompany the existence of national diversity in pluralist democracies. Tierney contends that the democratic plurinational state, characterized by the presence of more than one national group within the State, is a discrete category of multi-level polity which defies the standard classifications of liberal constitutionalism. Building upon this theoretical basis, this book then focusses upon recent developments toward the institutional accommodation of Catalonia, Quebec, and Scotland. Tierney examines the legal issues which arise from the challenges posed by national minorites within multinational democracies, to the constitutional and institutional structures of particular States, and also to some of the fundamental precepts of democratic constitutional theory and practice.