The Metropolitan Police Force of London dates to the early 19th Century and is largely the creation of Sir Robert Peel, who went on to become Prime Minister.

Peel had served as chief secretary for Ireland in 1812–1818 and laid the groundwork for a police force there. He became Home Secretary of the United Kingdom in 1821 and made a name for himself revolutionizing the penal system. Some private police forces had existed before this time, but they were rare and rarely organized. Among Peel's initiatives were a focus on preventing crime and reforming criminals, rather than relying strictly on terror and punishment. Prison reform was also a priority for Peel, and he achieved this by centralizing prison supervision.

The Metropolitan Police Act of 1829 established the police force of London. The members of the police, named after him, were called "Peelers" or "Bobbies." One of his more famous quotes was "The police are the public and the public are the police."

Members of the police had to physically fit, literate, aged 20–27, and 5'7" tall. Of course they had to have no criminal record. They worked all but five days a year, which they took as unpaid leave. Their salary was £1 a week. They had to wear their uniforms even when they were off duty and could not vote in elections.

They wore top hats and blue coats with tails. Peel believed that his policemen should not appear to be soldiers, so the uniforms were blue (not the red worn by the Army). They carried a pair of handcuffs, a wooden truncheon, and a wooden rattle; they would use the last to raise the alarm (with the rattle being replaced by a whistle a few decades later). Guns were used sparingly and were not usually carried.

The first members of the new police force started their patrols on Sept. 29, 1829. The initial force exceeded 1,000, with 895 constables patrolling the streets, 88 sergeants overseeing them, 20 inspectors doing separate work, eight superintendents overseeing all of the men in uniform, and two commissioners sitting over the top of everyone.

Peel enunciated Nine Principles of Policing:

1. To prevent crime and disorder, as an alternative to their repression by military force and severity of legal punishment.
2. To recognize always that the power of the police to fulfill their functions and duties is dependent on public approval of their existence, actions and behavior, and on their ability to secure and maintain public respect.
3. To recognize always that to secure and maintain the respect and approval of the public means also the securing of the willing cooperation of the public in the task of securing observance of laws.
4. To recognize always that the extent to which the cooperation of the public can be secured diminishes proportionately the necessity of the use of physical force and compulsion for achieving police objectives.
5. To seek and preserve public favor, not by pandering to public opinion, but by constantly demonstrating absolute impartial service to law, in complete independence of policy, and without regard to the justice or injustice of the substance of individual laws, by ready offering of individual service and friendship to all members of the public without regard to their wealth or social standing, by ready exercise of courtesy and friendly good humor, and by ready offering of individual sacrifice in protecting and preserving life.
6. To use physical force only when the exercise of persuasion, advice and warning is found to be insufficient to obtain public cooperation to an extent necessary to secure observance of law or to restore order, and to use only the minimum degree of physical force which is necessary on any particular occasion for achieving a police objective.
7. To maintain at all times a relationship with the public that gives reality to the historic tradition that the police are the public and that the public are the police, the police being only members of the public who are paid to give full-time attention to duties which are incumbent on every citizen in the interests of community welfare and existence.
8. To recognize always the need for strict adherence to police-executive functions, and to refrain from even seeming to usurp the powers of the judiciary of avenging individuals or the State, and of authoritatively judging guilt and punishing the guilty.
9. To recognize always that the test of police efficiency is the absence of crime and disorder, and not the visible evidence of police action in dealing with them.