This thesis examines the treatment and experiences of foreign national prisoners in England and Wales. It contains two main arguments. First, I contend that dominant prison theories rely on an outmoded understanding of the nation-state, and as a result, tend to ignore the effects of globalisation. Second, I argue that current prison practices reaffirm the boundaries of the British nation-state and promote an exclusionary notion of British citizenship. I conclude that research attuned to the affective, embodied dimensions of incarceration can help criminologists to develop a more ‘global’ perspective on state power. This argument begins and builds from ethnographic research. As a whole, the thesis is based on more than 200 interviews conducted over the course of a year in and around five men’s prisons in the north, southwest, and center of England. Structurally, it proceeds from a theoretical critique of prison studies, to an ethnographic account of prison life, to a conclusion about the purpose of prison scholarship. Thematically, it focuses on the relationship between identity and imprisonment, and in particular, on the ways in which normative beliefs about race, gender, sexuality, and class get infused in incarceration practices.