<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> <P> Constantinople was added at the First Council of Constantinople (381) and given authority initially only over Thrace . By a canon of contested validity, the Council of Chalcedon (451) placed Asia and Pontus, which together made up Anatolia, under Constantinople, although their autonomy had been recognized at the council of 381 . </P> <P> Rome never recognized this pentarchy of five sees as constituting the leadership of the state church . It maintained that, in accordance with the First Council of Nicaea, only the three "Petrine" sees of Rome, Alexandria and Antioch had a real patriarchal function . The canons of the Quinisext Council of 692, which gave ecclesiastical sanction to Justinian's decree, were also never fully accepted by the Western Church . </P>

With the establishment of the roman catholic church ecclesiastical order fall under