What is a "Regime of Truth"?

In this paper, I offer an overview of the ways in which Foucault defines and uses the concept of 'regime of truth' in his works between 1975 and 1980, focusing especially on his lectures at the College de France On the Government of the Living. There, I argue, a substantial shift takes place, which corresponds to the emergence of the dimension of subjectivity at the heart of the concept of regime of truth itself. This shift bears witness to Foucault's elaboration of a new critical project, namely that of a genealogy of our contemporary regime of truth 'indexed to subjectivity'.