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 of imperial peace in which the Roman world was largely free of armed conflict. The Principate system of government was established during his reign and lasted until the Crisis of the Third Century.

Julius Caesar was assassinated by a group of senators on the Ides of March of 44 BC during a meeting of the Senate at the Curia of Pompey of the Theatre of Pompey in Rome where the senators stabbed Caesar 23 times. They claimed to be acting over fears that Caesar's unprecedented concentration of power during his dictatorship was undermining the Roman Republic. At least 60 to 70 senators were party to the conspiracy, led by Marcus Junius Brutus, Gaius Cassius Longinus, and Decimus Junius Brutus Albinus. Despite the death of Caesar, the conspirators were unable to restore the institutions of the Republic. The ramifications of the assassination led to his martyrdom, the Liberators' civil war and ultimately to the Principate period of the Roman Empire.