A police force is any organized body of civilians directed by a government to maintain law enforcement and public order. While they often undergo combat training and are legally authorized to employ violence as necessary, they are distinct from the military in being a civil body entrusted only with domestic security.
The existence of the police as a distinct body independent of the military is a relatively recent development. In ancient times, the responsibility of law enforcement was often bestowed upon specific arms of a military, such as the Medjay or Phylakitai of Ptolemaic Egypt, or the Jinyiwei of Ming dynasty China – a secret police operated that enforced the emperor's will against judicial rulings and purged dissenters under the pretense of preserving societal harmony. Centuries later, military guards were often garrisoned within a city for its defense.
The concept of the police as a full-time, independently ran organized body, did not develop until the early 19th century; during the time of the French Revolution, France had a force dedicated to the prevention and investigation of crimes, led by the minister Charles Cochon de Lapparent whose development flourished under criminalist Eugène François Vidocq. The first officially recognised independent body was the United Kingdom's Metropolitan Police Service, founded in 1829.
The relationship between police and the Assassins can be complicated by the tendency of the latter to operate like vigilantes outside of the law in their quest to save humanity from the Templars. In one notable example, British police sergeant Frederick Abberline worked closely with Assassin twins Jacob and Evie Frye throughout 1868 in solving crimes and toppling the control of Templar Grand Master Crawford Starrick over London. However, the twins also founded a gang of their own, the Rooks, in their fight against Starrick's syndicate, the Blighters, and were by all means an extrajudicial party.
In later years, Abberline felt morally conflicted over his past partnership with the Assassins, but 2 decades later in 1888, he enlisted the aid of Evie Frye once again to stop the serial killer and rogue Assassin Jack the Ripper. Ultimately after Evie killed the Ripper, in spite of his misgivings, he agreed to her request to safeguard the mass murderer's fate and identity so as to protect the Assassins as a friend.
- Though Arno Dorian helps police chief Charles Cochon de Lapparent solve crimes in Assassin's Creed: Unity, police do not appear as a distinct gameplay faction until Assassin's Creed: Syndicate. There, they are color-coded blue on the mini-map. Although players are not penalized for killing them in free-roam, in various story memories, doing so costs full synchronization.
- The de-facto police in Assassin's Creed: Origins are referred to as phylakitai, both collectively and individually. This is incorrect as phylakitai is plural, with phylax being the singular equivalent. Even more confusingly, yet another version of the same word is used for the phylakes, again, both in plural and singular contexts, even though, again, the correct singular term is phylax.
- Assassin's Creed: Unity (first appearance)
- Assassin's Creed Chronicles: China (Mentioned only)
- Assassin's Creed: Syndicate
- Assassin's Creed: Origins