How did police departments form?
As societies became more urban and cities grew, maintaining security became a major priority for governments. Although threats in the ancient world and late antiquity were seen as external, it was also internal unrest that threatened cities and kingdoms. The development of policing was an important change that allowed cities to become safe enough to grow and prosper, but that history and its origin are complex.
In Mesopotamia and Egypt, but the 3rd millennium BCE, local officials appeared to have been tasked with rounding up criminals and bringing them to justice. The appearance of the first law codes during this time suggest crime was prevalent in cities and as urban places grew we begin to see an enforcement body, entrusted to local government officials, in charge with bringing in criminals and others who might have committed given crimes.
We learn more about the development of policing from ancient Greece. Although the term "police" derives from Greek origins, the concept of a civil force patrolling a city had not developed yet. Rather, the task of keeping relative calm and security in a city was something that was outsourced to slaves or servants who belonged to given officials. The Scythians were an ethnic group that came from Russia and Central Asia; some of these groups settled in Greece and warriors and slaves from these populations began to be used by city magistrates. The magistrates were responsible in using this force but most likely to also spy on the urban population to help maintain government control.
The city of ancient Rome probably had one of the most extensive policing forces, as the city's ancient size may have reached over a million inhabitants. Similar to Greece, magistrates used slaves to patrol and maintain order in Rome. Authority may have been problematic, as slaves were not seen as being able to give binding decisions such as arrested. Slaves, therefore, had to utilize the authority of their magistrates, and assume that their authority had credibility, in order to enforce their actions. However, by the period of Augusts in the late first century BCE and first century CE, the city of Rome developed the so-called vigiles, who acted as a group that were responsible for safety, security, and fire suppression (i.e, acted as a fire department). However, similar to earlier systems, these groups were privately owned slaves.
In ancient China, the development of the prefecture system by the mid-first millennium BCE, during the so-called Spring and Autumn period, included prefects given the responsibility with internal security in their regions. They became responsible in raising a force and enforcing an arrests of criminals. During the Tang dynasty, law enforcement became organized into a force called the Gold Bird Guards. This force was responsible in making arrests and was also assisted by citizens. The guards were composed of citizens.
In the Medieval period, policing began to emerge from municipalities that faced increasing crime and banditry in areas where kings could not or did not send soldiers or guards to protect citizens. One development during the Anglo-Saxon period and later was the concept of sheriff, a government official in charge of a shire or county. The office derives from a revee, who were officials responsible in a shire for security. Their jobs were to maintain order in shires and security, where in the early Medieval period banditry and raiding were common. During this time, policing was often at local levels such as shires or counties. Watchmen were often employed or appointed in towns to look out for any disruptive or illegal behavior. Local towns would often band together and form groups to protect travelers on roads. Local lords and nobles were largely responsible for maintaining order in their lands. Constables were sometime employed to help enforce laws in shires, villages, and towns.
The Santa Hermandades were one such group created in Spain who often kept pilgrims and others safe on roads. They were an association of individuals who saw their task was to keep order and security. Protective councils largely maintained the authority and power to protect citizens in many regions throughout Europe. In France, the positions of the Constable and Marshal of France were military positions that were also responsible for internal security. These officials were responsible for repelling internal strife but also keeping peace in the cities and highways of the country.
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.