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.
Constitutional reforms of Augustus
With the legitimate government of the Republic defeated, Caesar set about initiating his own constitutional reforms. Caesar immediately set about consolidating the various offices of the Republic into himself. He was first appointed Dictator in 49 BC but resigned it within eleven days. In 48 BC, he was re-appointed dictator, only this time for an indefinite period, and in 46 BC, he was appointed dictator for ten years. Finally, in 44 BC, Caesar was appointed Dictator for life. In addition to holding the dictatorship, Caesar held the Consulship in 48 BC, 46 BC, 45 BC (without colleague), and 44 BC. By holding the Dicatorship and the Consulship simultaneously, Caesar's "imperium" ("military authority") was supreme and all provincial governors were subservant to his will. With his unchallengeable command authority, Caesar could remove any civil magistrate or military commander from office at his pleasure.