Augustus was granted sole "imperium" within the city of Rome itself, in addition to being granted proconsular imperium maius and tribunician authority for life. Traditionally, proconsuls (Roman province governors) lost their proconsular "imperium" when they crossed the Pomerium – the sacred boundary of Rome – and entered the city. In these situations, Augustus would have power as part of his tribunician authority but his constitutional imperium within the Pomerium would be less than that of a serving consul. That would mean that, when he was in the city, he might not be the constitutional magistrate with the most authority. Thanks to his prestige or "auctoritas", his wishes would usually be obeyed, but there might be some difficulty. To fill this power vacuum, the Senate voted that Augustus's imperium proconsulare maius (superior proconsular power) should not lapse when he was inside the city walls. All armed forces in the city had formerly been under the control of the urban praetors and consuls, but this situation now placed them under the sole authority of Augustus.