27-14 BC Ancient Rome, Augustus AE As, 25mm 9.4g Ancient Grades f. Gaius Julius Caesar Augustus, also known as Octavian, was the founder of the Roman Empire. He reigned as the first Roman emperor from 27 BC until his death in AD 14. The reign of Augustus initiated an imperial cult, as well as an era associated with imperial peace (the Pax Romana or Pax Augusta) in which the Roman world was largely free of armed conflict (aside from expansionary wars and the Year of the Four Emperors, the latter of which occurring after Augustus' reign). The Principate system of government was established during his reign and lasted until the Crisis of the Third Century.