power to affect the actions of provincial governors. The powers of the tribunes were severely curtailed during the constitutional reforms of the dictator Sulla in 81 BC. Although many of these powers were restored in further reforms of 75 BC and 70 BC, the prestige and authority of the tribunes had been irreparably damaged. In 48 BC, the senate granted tribunician powers (tribunicia potestas, powers equivalent to those of a tribune without actually being one) to the dictator Julius Caesar. Caesar used them to prevent the other tribunes interfering with his actions. In 23 BC, the senate granted the same power to Augustus, the first Roman emperor, and from that point onwards it was regularly granted to each emperor as part of their formal titles. Under the Roman Empire, the tribunes continued to be elected, but had lost their independence and most of their practical power. The office became merely a step in the political careers of plebeians who aspired toward a seat in the senate. Military tribunes The tribuni militum, known in English as military tribunes or literally, tribunes of the soldiers, were elected each year along with the annual magistrates. Their number varied throughout Roman history, but eventually reached twenty-four. These were usually young men in their late twenties, who aspired to a senatorial career. Each tribune would be assigned to command a portion of the Roman army, subordinate to the magistrates and promagistrates appointed by the senate, and their legates. Within each of the legions, various middle-ranking officers were also styled tribune. These officers included: Tribunus laticlavius, a senatorial officer, second in command of a legion; identified by a broad stripe, or laticlavus. Tribunus angusticlavius, an officer chosen from among the equites, five to each legion; identified by a narrow stripe, or angusticlavus. Tribunus rufulus, an officer chosen by the commander. Tribunus vacans, an unassigned officer in the Late Roman army; a member of the general's staff. Tribunus cohortis, an officer commanding a cohort, part of a legion usually consisting of six centuries. Tribunus cohortis urbanae, commander of one of the urban cohorts, a sort of military police unit stationed at Rome. Tribunus sexmestris, a tribune serving a tour of duty of only six months; there is no evidence to identify this officer as a cavalry commander, as sometimes stated in modern literature. In the late Roman army, a tribunus was a senior officer, sometimes called a