To a large extent, policing remained ad hoc for much of the Medieval period. In the 17th century, with religious wars rampant in Europe, new forces were created that became responsible for policing in England and France. The term "police" is used during the period of the English Civil War, as a force to protect citizens and maintain order was created during a period of instability. In Paris, the first dedicated police department was created. The responsibility of the department was to protect citizens and remove any threat of disturbances. Similar to what happened in Rome, it was population increase and rise of crime that led to the development and impetus to create a more organized force to police the city. The police were led by a police lieutenant who was assisted by commissioners that maintained control of different districts within Parsi. This system by the late 17th century was extended to the entire country, creating effectively the first national police force.
In Britain, unofficial positions such as watchmen in towns, that had developed in the Medieval period, began to become more formalized in the 18th century, where watchmen began being paid. The position of constable became more professional and became more official government positions. The night watchmen became regulated through an act of Parliament by 1737. The act specified how many constables should be on duty during any given night for the city of London. The Bow Street Runners effectively became London's first paid police force in 1749. This was a group of men who would use funds given by the government to help solve crimes and keep peace. This force had an office where citizens would come to report offenses. In effect, the police force acted more like detectives, while constables continued to serve as something comparable to police patrols. In effect, policing became distinguished into branches that involved investigations and protection.
By the early 1800s, London became the largest city and had continued to grow. Its existing policing was severely constrained for the growing population. The Metropolitan Police act of 1829 established London's police force. The police in London were distinctly organized to look different from the military, where they were not issued weapons and had very different uniforms. The 1835 Municipal Corporations Act then began to broaden policing throughout Britain by expanding policing to 178 boroughs, creating now a national effort for policing. This and the French model then became the models in which other states began to develop their major urban and national policing forces.