Augustus' reign has laid the foundations of a regime that is to last 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 will become 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 (Constantinople).

In many languages, Caesar becomes the word for Emperor, as in the German Kaiser and in the Bulgarian and subsequently Russian Tsar.

The cult of Divus Augustus will continue until the state religion of the Empire is 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 are inscribed throughout the Empire upon his death.

The inscriptions in Latin feature translations in Greek beside it, and are inscribed on many public edifices, such as the temple in Ankara dubbed the Monumentum Ancyranum, called the "queen of inscriptions" by historian Theodor Mommsen.

There are a few known written works by Augustus that have survived, including his poems Sicily, Epiphanus, and Ajax, an autobiography of 13 books, a philosophical treatise, and his written rebuttal to Brutus' Eulogy of Cato.

However, historians are able to analyze existing letters penned by Augustus to others for additional facts or clues about his personal life.