Octavius, later awarded the title of Augustus, establishes the Roman empire after defeating Marc Antony and Cleopatra in 31 B.C. The eastern Mediterranean is one of the richest regions of the empire and succeeding Roman emperors struggle to maintain order there. Opposition to Roman rule is particularly strong in Judaea. In 313 A.D., the emperor Constantine removes the proscriptions against Christianity and seventeen years later relocates the capital east to the city of Byzantium (Constantinople). In 391 A.D., Theodosius declares Christianity the sole official religion of the empire, banning all others. Upon his death in 395 A.D., his realm is formally divided, the eastern half of which will come to be known as the Byzantine empire.