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, firefighting 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. A praefectus vigilum, or "Prefect of the Watch" was put in charge of the vigiles, Rome's fire brigade and police. With Rome's civil wars at an end, Augustus was also able to create a standing army for the Roman Empire, fixed at a size of 28 legions of about 170,000 soldiers. This was supported by numerous auxiliary units of 500 non-citizen soldiers each, often recruited from recently conquered areas. With his finances securing the maintenance of roads throughout Italy, Augustus installed an official courier system of relay stations overseen by a military officer known as the praefectus vehiculorum. Besides the advent of swifter communication among Italian polities, his extensive building of roads throughout Italy also allowed Rome's armies to march swiftly and at an unprecedented pace across the country. In the year 6 Augustus established the aerarium militare, donating 170 million sesterces to the new military treasury that provided for both active and retired soldiers. One of the most enduring institutions of Augustus was the establishment of the Praetorian Guard in 27 BC, originally a personal bodyguard unit on the battlefield that evolved into an imperial guard as well as an important political force in Rome. They had the power to intimidate the Senate, install new emperors, and depose ones they disliked; the last emperor they served was Maxentius, as it was Constantine I who disbanded them in the early 4th century and destroyed their barracks, the Castra Praetoria. Although the most powerful individual in the Roman Empire, Augustus wished to embody the spirit of Republican virtue and norms. He also wanted to relate to and connect with the concerns of the plebs and lay people. He achieved this through