This chapter deals with medical practice in Western Europe, the institutions and circumstances that shaped it, and their evolution during the period from about 1050 to 1500. Only studies of medical profession can provide an accurate sense of the dynamics that shaped medieval health care and the enormous geographical and chronological variety of the institutions, laws, and practices that constituted it. Health care is formed, in which patients and their families moved back and forth between secular and saintly healers: 'between doctors and holy shrines', as the account of another of Gilbert's miracles specified. The effect of urbanization was to support a larger, more diverse, and more specialized community of medical practitioners. The chapter focuses on two principal kinds of medical institutions elaborated in the fourteenth and fifteenth centuries: those concerned with regulating practice and defending the interests of practitioners, and those concerned with mobilizing medical expertise.