This article has two interrelated aims. First, the article goes beyond law and places the discussions on nationality in the broader literature on citizenship, also drawing on social sciences, political theory and moral philosophy. The ensuing conceptual, historical and multidisciplinary account highlights the long pedigree of the idea of citizenship, the manifold conceptions of citizenship that have developed over time (including supra-national, sub-national and transnational citizenship). The article demonstrates how the changing spatialities of citizenship culminated in a focus on the nation-state, and the emergence of legal citizenship or nationality, reflecting the legal bond between an individual and a state. It was also noted that in several respects the parameters of nationality keep changing. More particularly, four developments have been highlighted that circumscribe the sovereign right of states to determine who are their nationals, both legally and through de facto pressures. Secondly, this contribution provides the overarching framework for the special issue while identifying the salient discussion points regarding nationality and international law that will be teased out in the articles of the special issue. The article ends with a brief overview of the articles that make up the special issue.