Uncertainty is central to the governance of citizenship, but in ways that erase, even deny, this uncertainty. This book investigates uncertain citizenship from the unique vantage point of ‘citizenisation’: twenty-first-century integration and naturalisation measures that make and unmake citizens and migrants, while indefinitely holding many applicants for citizenship in what Fortier calls the ‘waiting room of citizenship’. Fortier’s distinctive theory of citizenisation foregrounds how the full achievement of citizenship is a promise that is always deferred: if migrants and citizens are continuously citizenised, so too are they migratised. Citizenisation and migratisation are intimately linked within the structures of racial governmentality that enables the citizenship of racially minoritised citizens to be questioned and that casts them as perpetual migrants. Drawing on multi-sited fieldwork with migrants applying for citizenship or settlement and with intermediaries of the state tasked with implementing citizenisation measures and policies, Fortier brings life to the waiting room of citizenship, giving rich empirical backing to her original theoretical claims. Scrutinising life in the waiting room enables Fortier to analyse how citizenship takes place, takes time and takes hold in ways that conform, exceed, and confound frames of reference laid out in both citizenisation policies and taken-for-granted understandings of ‘the citizen’ and ‘the migrant’. Uncertain Citizenship’s nuanced account of the social and institutional function of citizenisation and migratisation offers its readers a grasp of the array of racial inequalities that citizenisation produces and reproduces, while providing theoretical and empirical tools to address these inequalities.