Augustus
Augustus' reign laid the foundations of a regime that lasted, in one form or another, for nearly fifteen hundred years through the ultimate decline of the Western Roman Empire and until the Fall of Constantinople in 1453. Both his adoptive surname, Caesar, and his title "Augustus" became the permanent titles of the rulers of the Roman Empire for fourteen centuries after his death, in use both at Old Rome and at New Rome. In many languages, "Caesar" became the word for "Emperor", as in the German "Kaiser" and in the Bulgarian and subsequently Russian "Tsar" (sometimes Csar or Czar). The cult of "Divus Augustus" continued until the state religion of the Empire was changed to Christianity in 391 by Theodosius I. Consequently, there are many excellent statues and busts of the first emperor. He had composed an account of his achievements, the "Res Gestae Divi Augusti", to be inscribed in bronze in front of his mausoleum. Copies of the text were inscribed throughout the Empire upon his death. The inscriptions in Latin featured translations in Greek beside it, and were inscribed on many public edifices, such as the temple in Ankara dubbed the "Monumentum Ancyranum", called the "queen of inscriptions" by historian Theodor Mommsen.
Constitution of the Roman Empire
At this point, the Senate also granted Octavian the title ""augustus"" and the position of "princeps senatus", or the first Senator. When Augustus, as Octavian was renamed, gave up the consulship in 23 BC, the Senate granted him an expansion of his proconsular authority, with legal authority at the same level as those of the normal consuls. Furthermore, Augustus expanded the use of the tribunician powers granted in 36 BC, which allowed him to interfere in administration, convoke the people, propose legislation, veto other political bodies, etc. After these final reforms had been instituted, Augustus never again altered his constitution, although he did periodically assume the office of censor to affect changes in the Senatorial rolls (alone in 8 BC, and with Tiberius in AD 14) and hold the consulship (twice after 23 BC). When, in 20 BC, a famine in Rome led to the people offering Augustus the dictatorship, he refused, instead taking on the "cura annonae": the administration of the grain supply. And when the ten-year term of his proconsular authority elapsed, he continued the fiction of the temporary nature of his authority, having it renewed in 18 BC, 13 BC, 8 BC, 3 BC, and 8 AD. While there were minor changes in the provinces which he governed by nature of his proconsular authority ("Gallia Narboensis" and "Cyprus" were returned to the Senate's administration in 22 BC), its overriding nature did not change until after his death.