Jonathan Klaaren blends legal and social history in this engaging account of early conceptions of South African citizenship. He argues that distinctively South African notions of citizenship and nationality come out of the period 1897 to 1937, through legislation and official practices employing the key concept of ‘prohibited immigrant’ and seeking to regulate the mobility of three population groups: African, Asian and European. Further, he makes the case that the regulation and administration of immigrants from the Indian sub-continent, in particular, provided the basis for the vision and eventual reality of a unified, although structurally unequal, South African population. This book fits into the growing field of Mobility Studies, which seeks to understand and document the migration of people both within and across national borders, while exploring the origins of those borders. In addition to nationality and citizenship, it touches on African pass laws, the origins of the Public Protector, the scheme importing Chinese labour to the gold mines, the development of internal bureaucratic legality, and India-South Africa intra-imperial relations. With its attention to the role of law in state-building and its understanding of the central place of implementation and administrative law in migration policy, this book offers a distinctive focus on the relationship between migration and citizenship.