Since the French Revolution, state violence has been based on a political fiction which has the force of law: the use of force against resistance to laws is always impersonal and lawful. Yet, an analysis of 3,725 collective and violent rebellions reveals that the police forces react in various ways, obeying national orders or adapting to local circumstances, acting out of their political background or professional culture. However, beyond this empiricism, a striking reversal in favor of the police forces occurred between 1800 and 1859 , with a concomitant fall in the number of rebellions, as well as in the degree of violence. Such phenomena are deeply linked to a monopolization of the use of arms by the police forces and a change in the forms of social movements.