Justinian I is traditionally known as Justinian the Great .
Justinian I officially known as Flavius Petrus Sabbatius Iustinianus Augustus or Φλάβιος Πέτρος Σαββάτιος Ἰουστινιανός or Flávios Pétros Sabbátios Ioustinianós , 482 - November 14 , 565 , traditionally known as Justinian the Great and also Saint Justinian the Great in the Eastern Orthodox Church , was a Byzantine East Roman emperor from 527 to 565 .
Justinian I