<P> In 533 Roman Emperor Justinian in Constantinople launched a military campaign to reclaim the western provinces from the Arian Germans, starting with North Africa and proceeding to Italy . His success in recapturing much of the western Mediterranean was temporary . The empire soon lost most of these gains, but held Rome, as part of the Exarchate of Ravenna, until 751 . </P> <P> Justinian definitively established Caesaropapism, believing "he had the right and duty of regulating by his laws the minutest details of worship and discipline, and also of dictating the theological opinions to be held in the Church". According to the entry in Liddell & Scott, the term orthodox first occurs in the Codex Justinianus: "We direct that all Catholic churches, throughout the entire world, shall be placed under the control of the orthodox bishops who have embraced the Nicene Creed ." </P> <P> By the end of the 6th century the Church within the Empire had become firmly tied with the imperial government, while in the west Christianity was mostly subject to the laws and customs of nations that owed no allegiance to the emperor . </P> <P> Emperor Justinian I assigned to five sees, those of Rome, Constantinople, Alexandria, Antioch and Jerusalem, a superior ecclesial authority that covered the whole of his empire . The First Council of Nicaea in 325 reaffirmed that the bishop of a provincial capital, the metropolitan bishop, had a certain authority over the bishops of the province . But it also recognized the existing supra - metropolitan authority of the sees of Rome, Alexandria and Antioch, and granted special recognition to Jerusalem . </P>

Who made christianity the roman empire's official religion