Caesar Augustus (63 BC – 14 AD) was the first Roman emperor, reigning from 27 BC until his death in AD 14. His status as the founder of the Roman Principate has consolidated a legacy as one of the most effective and controversial leaders in human history. Originally named Gaius Octavius, he was adopted by his great uncle, Gaius Julius Caesar - by his last will and testament - making Octavian his son and sole heir. Caesar Augustus was one of ancient Rome's most successful leaders who led the transformation of Rome from a republic to an empire. During his reign, Augustus restored peace and prosperity to the Roman state and changed nearly every aspect of Roman life.