This chapter looks at the making of knowledge in the city of Vienna by considering, first, the relationship between the court and the city, with all its confessional, political and spatial tensions before and after the transfer of the court to Prague and its return at the beginning of the seventeenth century. It examines a specific ‘place of knowledge’, the Imperial Library. The chapter focuses on the interaction between the city and the library at a time of change in the very conception of the empire it is also possible to shed new light on the type of epistemology typical of Vienna beyond the early modern period. The massive Imperial Library in Vienna, identified since the 1920s with the Austrian National Library, is not an exception and plays an active role as a local urban cultural institution.