u/TargetRupertFerris

Ever since Constantine the Great and his father, Constantius Chlorus, the Roman titulatute for the Emperors were typically Imperator Caesar Flavius [Insert Name] Augustus.

But by the fall of the Heraclian dynasty, such style for Roman Emperors seemingly fell out of use, with later Byzantine Emperors using simple regnal names and eventually using their family names to emphasize their nobles house such as Nikephoros II Phokas and Constantine XI Dragases Palaiologos.