The history of the constitution of the Roman Empire begins with the establishment of the Principate in 27 BC and is considered to conclude with the abolition of that constitutional structure in favour of the Dominate at Diocletian's accession in AD 284. The Roman Empire's constitution emerged as a transformation of the late Roman Republic's constitution, utilising various late republican precedents, to legitimise the granting of incredible legal powers to one man and the centralisation of legal powers into bodies which that man controlled. The creation of the Principate and the Roman Empire is traditionally dated to 27 BC with the first Augustan constitutional settlement, where Octavian, the victor of the final war of the Roman Republic, gave up his extraordinary powers and was vested with proconsular authority over the imperial provinces, which he held along with the tribunician power granted to him by the Senate in 36 BC. Concurrently, he held the Roman consulship, granting him authority within the ordinary legal structure which did not exceed any of the other magistrates. By holding various republican offices, Augustus, as Octavian was known after 27 BC, was able to disguise the autocratic nature of his regime and claim a restoration of the Republic. After more constitutional changes in 23 BC, Augustus was granted greater proconsular authority over all imperial provinces, which allowed him to override any other Roman governors, marking the completion of the various offices that most Roman emperors would hold until the transformation of the Principate into the Dominate in the late third century. Various other changes were affected over the course of the Empire, reducing the electoral powers of the various Roman assemblies and shifting those powers to the Senate, as well as doing away with elections entirely in favour of appointments by the emperor. Augustus' constitutional reforms Octavian returned to Rome two years after defeating Mark Antony at the Battle of Actium. With Mark Antony's defeat, no one remained to oppose Octavian. Decades of war had taken a terrible toll on the People of Rome. The political situation was unstable, and there was a constant threat of renewed warfare. Octavian's arrival alone caused a wave of optimism to ripple throughout Italy. As soon as he arrived, he began addressing the problems that were plaguing Rome. He declared a general amnesty for the former supporters of his enemies, and provided land for over 120,000 former soldiers. As soon