A city guard, city watch, town guard, or town watch was a law enforcement and security formation found in many countries and historical periods, usually subordinate to the local municipal government. Historically many cities had their own guard formations, which doubled as police and military forces in times of need.
With the unification of laws and centralization of state power (e.g. the Municipal Police Act of 1844 in New York City, United States), such formations became increasingly incorporated into state-run police forces.