Octavian as son of a Roman god 
On 1 January 42 BC, nearly two years after the assassination of Julius Caesar on 15 March 44 BC, but before the final victory of the Second Triumvirate over the conspirators who had taken his life, the Roman Senate recognised him as a divinity. He was therefore referred to as Divus Iulius (the divine Julius), and his adopted son styled himself Divi filius (son of the deified one, son of the god). The fuller form, "divi Iuli filius" (son of the divine Julius) was also used.
Octavian used the title divi filius to advance his political position, finally overcoming all rivals for power within the Roman state. The title was for him "a useful propaganda tool", and was displayed on the coins that he issued.
Other emperors 
Since Augustus himself (the title "Augustus" was officially conferred on Octavian in 27 BC) and some other Roman Emperors were deified after death, the title Divi Filius was also applied to some of Augustus's successors: Tiberius, Nero, and Domitian.
Distinction from "Dei Filius" 
The term used for Julius Caesar and the deified emperors was "divus", not "deus', the word used for gods such as Jupiter and Mars. Augustus was thus called "Divi Filius", not "Dei Filius", the phrase that Christians used of Jesus.
- Syme, Ronald (2002) . The Roman Revolution. Oxford: Oxford University Press. p. 202. ISBN 0-19-280320-4.
- 'Augustus' Gaius Julius Octavius
- Inscription on Porta Tiburtina in Rome
- "Ostentatiously rejecting divinity on his own account, he rose to power via Caesar's divine image instead" (Augustus, by Pat Southern, p. 63).
- Coins of the Emperor Augustus; examples are a coin of 38 B.C. inscribed "Divi Iuli filius", and another of 31 B.C. bearing the inscription "Divi filius" (Auguste vu par lui-même et par les autres by Juliette Reid).
- Tae Hun Kim, «The Anarthrous υἱὸς θεοῦ in Mark 15,39 and the Roman Imperial Cult»