Am currently working my way through Foucault's Security, Territory, and Population, a collection of transcribed thoughts from the early 1970s and lecture notes from a series of lectures Foucault gave at the Collége de France in the late 1970s (1977-1978).
Also see Security, Territory, Population on Wikipedia.
Here's a quote from the Stanford Encyclopedia of Philosophy talking about an aspect of Foucault's study of institutions of authority:
The results of exams are recorded in documents that provide detailed information about the individuals examined and allow power systems to control them (e.g., absentee records for schools, patients’ charts in hospitals). On the basis of these records, those in control can formulate categories, averages, and norms that are in turn a basis for knowledge. The examination turns the individual into a “case”—in both senses of the term: a scientific example and an object of care. Caring is always also an opportunity for control.