Justinian I (/dʒʌˈstɪniən/; Latin: Flavius Petrus Sabbatius Justinianus Augustus, Greek: Φλάβιος Πέτρος Σαββάτιος Ἰουστινιανός Flábios Pétros Sabbátios Ioustinianos) (c. 482 – 14 November 565), commonly known as Justinian the Great, was Byzantine Emperor from 527 to 565. During his reign, Justinian sought to revive the Empire's greatness and reconquer the lost western half of the historical Roman Empire.