Gaius Octavius Thurinus, was adopted by his great-uncle Julius Caesar in 44 BC, and between then and 27 BC was officially named Gaius Julius Caesar. After 27 BC, he was named Gaius Julius Caesar Augustus. Because of the various names he bore, it is common to call him Octavius when referring to events between 63 and 44 B.C., Octavian (or Octavianus) when referring to events between 44 and 27 B.C., and Augustus when referring to events after 27 B.C. Augustus or Octavian was the first and possibly greatest Roman emperor, he founded the Roman Empire after defeating Mark Antony and Cleopatra. As emperor, Augustus reformed the coinage and the military, and embarked on a huge building program all across the empire. After a long reign of 41 years, from 27 B.C. to 14 A.D., he died at the age of 77.