Many consider Augustus to be Rome's greatest emperor; his policies certainly extended the Empire's life span and initiated the celebrated "Pax Romana" or "Pax Augusta". The Roman Senate wished subsequent emperors to "be more fortunate than Augustus and better than Trajan". Augustus was intelligent, decisive, and a shrewd politician, but he was not perhaps as charismatic as Julius Caesar and was influenced on occasion by Livia (sometimes for the worse). Nevertheless, his legacy proved more enduring. The city of Rome was utterly transformed under Augustus, with Rome's first institutionalized police force, fire fighting force, and the establishment of the municipal prefect as a permanent office. The police force was divided into cohorts of 500 men each, while the units of firemen ranged from 500 to 1,000 men each, with 7 units assigned to 14 divided city sectors.