In ancient Rome, any of various high officials with primarily judicial and administrative responsibilities.
In the early republic, a prefect of the city ( praefectus urbi ) took over the consul 's duties during their absence from Rome. The office lost some importance after the introduction of praetor s (mid 4th century BC). Augustus revitalized the office when he appointed five prefects to supervise the city government, the fire brigade, the grain supply, and the Praetorian Guard . The praetorian prefects acquired great power and often became virtual prime ministers.