During the political and military upheavals between the 1770s and 1820s, societies and states across the Atlantic world grappled with intricate issues of political belonging and sovereignty. Along with the rise of new concepts of national citizenship, older concepts of monarchical or imperial subjecthood underwent fundamental changes. While scholars tend to ascribe these transformations to revolutionary innovation, the movement of hundreds of thousands of refugees fleeing revolutions and violent conflict was no less important in reshaping the terms of political membership. In response to these migrations, national and colonial governments passed legislation meant to control the mobility of foreign refugees. Based on the case of three men of colour, the sons of Haitian refugees, deported from Jamaica in 1823, this article explores the wider impact the regulation of alien status had. The 1823 incident set off a major legal battle and a sprawling debate about the terms of membership in the transforming British Empire. The affair raised fundamental questions about the status and rights of foreigners, the definition of who was a subject of the British Crown, and about how sovereignty was to be conceived in a period of continuous territorial transfers and military occupations.