What historical group was known for patrolling cities at night and signaled for help using rattles?

The Night Watch is the correct choice because this group was specifically established in many cities to maintain order and provide security during the nighttime hours. Historically, members of the Night Watch would patrol the streets after dark, keeping an eye out for any disturbances or criminal activity. They were often volunteers or appointed individuals and played a vital role in the law enforcement of the time.

The use of rattles as a signaling device was a notable feature of their method of communication; they would rattle these instruments to alert other members of the watch or to call for assistance if they encountered trouble. This practice of signaling created a networked response system, which was crucial before modern communication methods were available.

In contrast, while Town Guards were organized in some regions, they generally served with a more structured military-style focus rather than specifically patrolling at night. City Patrols and Neighborhood Watches, while related to community safety, developed later and differ in function as they focus more on crime prevention and community vigilance rather than the historical nighttime role of the Night Watch.