Constable

A constable is a person doing a certain job, most commonly in law enforcement. The work and role of a constable can vary a lot in different countries.
Historically, the word "constable" comes from the Latin, "comes stabuli", count of the stables. It came from the Eastern Roman Empire. Originally, the constable was the person who kept the horses of a lord or monarch. The title was later used in the monarchies of medieval Europe. In many countries, the constable became a high military rank and great officer of State such as, the Constable of France.
In modern times, constables are law enforcement officers. In the United Kingdom, Commonwealth of Nations and some European countries, a constable is the lowest rank of police officer. In the United States a constable is usually an elected peace officer, with less powers than a sheriff. However, in the Channel Islands a constable is an elected office-holder at the parish level.
Historically, a constable could also be someone in charge of the defence of a castle. Even today, there is a Constable of the Tower of London.
It is a similar position to Marshal, which comes from Old High German "marah" "horse" and "schalh" "servant", and originally meant "stable keeper", which has a similar etymology.