Chapter 3 considers the role of nationality in the protection and enjoyment of human rights. It examines the history of international law’s involvement in and regulation of matters concerning nationality, thereby providing a crucial link between Chapter 2 and Chapters 4, 5, and 6. It begins by reviewing the traditional position whereby considerations of nationality, including the practice of re-admission for non-nationals, fell within the reserved domain of states through their own nationality laws. The chapter outlines the evolution of international human rights law and its impact on state discretion, such that in many instances, deprivation of nationality (i.e. denial of nationality and/or withdrawal of nationality) may now well violate norms of international law. The chapter therefore examines deprivation of nationality, and the consequences for the persons concerned, in treaty law, UN documents, and the jurisprudence of international and regional courts.