Question

What marked the official transition from Roman Republic to Roman empire?

Answer 1

The correct answer is "When Augustus, formally known as Octavian became Emperor of Rome".

Octavian rose to power defeating Mark Antony and Lepidus for the control of the territories of the Roman Republic. The consolidation of all power into a single ruler declared emperor, officially indicates the transition towards an empire for Rome. Once Octavian became emperor, he applied severe fiscal, political and military reforms which led the way towards a more absolutist government.

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