The paper gives an account of the changing patterns of policing in a medium-sized French town, Grenoble, between 1880 and 1930.Two lines of transformation are emphasized. First, a trend towards the enactment of nationwide rules, procedures and controls is fuelled both by the development of centredriven policies and by the professionalization of police personnel across the country. Meanwhile, urban growth gives a significant impulse to a process of local embeddedment of the police work and forces. Boths trends contribute to the constitution of a French republican model of policing based upon a balance between centralization and local control.