Final answer:
The Vigiles were responsible for night patrols and firefighting in ancient Rome, organized into cohorts and primarily composed of freed slaves and lower-class citizens, distinct from the Praetorian Guard and Urban Cohorts.
Step-by-step explanation:
The group initially responsible for patrolling the streets at night and firefighting in ancient Rome was the Vigiles. Unlike the Praetorian Guard, which was tasked with protecting the emperor, or the Urban Cohorts that dealt with day-to-day policing, the Vigiles primarily acted as a fire brigade and night watch.
Established during the reign of Augustus in the late 1st century BCE, the Vigiles were organized into cohorts of approximately 1,000 men, each responsible for a different region of the city. These men were mainly freed slaves and lower-class citizens trained not just for firefighting but also for dealing with petty criminals and maintaining order after dark.
Their existence highlights the complexity and advancement of Roman urban planning and social organization, recognizing the need for specialized roles to maintain public order and safety within the empire's capital. The establishment of the Vigiles marked a critical step toward a more structured approach to urban management and disaster prevention in one of the world's most influential civilizations.