In 38 BC, Octavian replaced his praenomen "Gaius" and nomen "Julius" with Imperator, the title by which troops hailed their leader after military success, officially becoming Imperator Caesar Divi Filius.
In 27 BC, following his defeat of Mark Antony and Cleopatra, the Roman Senate voted new titles for him, officially becoming Imperator Caesar Divi Filius Augustus [REF].