Augustus (Octavian) was the first Roman Emperor.

His rule and ascension of the Rome empire (Principate Era) ended republic rule at Rome. Roman Emperors and Empresses were rulers of the Roman Empire, wielding power over its citizens and military.

Note from history: Octavian was the founder of the Roman Empire. He ruled the Empire for 41 years, right until his death in AD 14

This might be interesting: Augustus never claimed the title of the first Emperor for himself, even though it was him who led Rome's transformation from a republic to an empire. Did you know that he was a nephew of Julius Caesar?

More Info: en.wikipedia.org