The development of the modern police in Western Europe can be characterized as the history of a represssive tool of state power. In the course of this development, the police have been nationalized, i.e., police control has been transferred from local to national authorities, the police have been reorganized to cover the whole territory of the state, and the power of the police has been assumed by the state. The modern police are termed repressive because their primary task is to maintain political order, especially by squelching political opposition. A process of police nationalization took place in two phases: from 1789 to 1815, under French domination, the countries of Western Europe created police authorities on a national level; from 1815 to 1850 the police were intensely militarized in anticipation of the revolution. During the second phase of this development the police departments were expanded and transformed to carry out police operations in the modern sense. Reorganization involved introduction of special police units to assure police powers in gathering information and in quelling disturbances of public security and order. Militarization escalated still further in 1918-19, with the introduction of police troups organized along military lines. The nationalization process of the police was strongly influenced by internal power struggles involving groups with an international character, e.g., the revolution of 1917-19. Research on the development of the police in specific countries is recommended. Notes and a bibliography are supplied.