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.
Augustus
A final reason for the Second Settlement was to give the Principate constitutional stability and staying power in case something happened to Princeps Augustus. His illness of early 23 BC and the Caepio conspiracy showed that the regime's existence hung by the thin thread of the life of one man, Augustus himself, who suffered from several severe and dangerous illnesses throughout his life. If he were to die from natural causes or fall victim to assassination, Rome could be subjected to another round of civil war. The memories of Pharsalus, the Ides of March, the proscriptions, Philippi, and Actium, barely twenty-five years distant, were still vivid in the minds of many citizens. Proconsular imperium was conferred upon Agrippa for five years, similar to Augustus' power, in order to accomplish this constitutional stability. The exact nature of the grant is uncertain but it probably covered Augustus' imperial provinces, east and west, perhaps lacking authority over the provinces of the Senate. That came later, as did the jealously guarded tribunicia potestas. Augustus' accumulation of powers were now complete. In fact, he dated his 'reign' from the completion of the Second Settlement, 1 July 23 BC.