This chapter is the main theoretical chapter that introduces and engages with Foucault’s theorising on biopower and biopolitics, paying particular attention to the death function in biopolitics and to distinctions between sovereignty and biopolitics. The chapter then places biopolitics into the wider framework of governmentality, with a special focus on the different meanings of governmentality and the key characteristics of liberal and neoliberal governmentalities. Finally, it provides a critical overview of biopolitics and governmentality studies with a view to establishing productive ways of operationalising Foucault’s conceptual and methodological tools for the analysis of the international.