Christianity as the Roman state religion
In the year before the Council of Constantinople in 381, the Trinitarian version of Christianity became the official religion of the Roman Empire when Emperor Theodosius I issued the Edict of Thessalonica in 380,[1] which recognized the catholic orthodoxy[a] of Nicene Christians as the Roman Empire's state religion.[3][4][5][6] Historians refer to the Nicene church associated with emperors in a variety of ways: as the catholic church, the orthodox church, the imperial church, the Roman church, or the Byzantine church, although some of those terms are also used for wider communions extending outside the Roman Empire.[7] The Eastern Orthodox Church, Oriental Orthodoxy, and the Catholic Church all claim to stand in continuity from the Nicene church to which Theodosius granted recognition.
Earlier in the 4th century, following the Diocletianic Persecution of 303–313 and the Donatist controversy that arose in consequence, Constantine the Great had convened councils of bishops to define the orthodoxy of the Christian faith and to expand on earlier Christian councils. A series of ecumenical councils convened by successive Roman emperors met during the 4th and the 5th centuries, but Christianity continued to suffer rifts and schisms surrounding the theological and christological doctrines of Arianism, Nestorianism, Miaphysitism, and Dyophysitism. In the 5th century, the Western Roman Empire decayed as a polity; invaders sacked Rome in 410 and in 455, and Odoacer, an Arian barbarian warlord, forced Romulus Augustus, the last nominal Western Emperor, to abdicate in 476. However, apart from the aforementioned schisms, the church as an institution persisted in communion, if not without tension, between the East and West. In the 6th century, the Byzantine armies of the Byzantine Emperor Justinian I recovered Italy and other regions of the Western Mediterranean shore. The Byzantine Empire soon lost most of these gains, but it held Rome, as part of the Exarchate of Ravenna, until 751, a period known in church history as the Byzantine Papacy. The early Muslim conquests of the 7th–9th centuries would begin a process of converting most of the then-Christian world in the Levant, Middle East, North Africa, regions of Southern Italy and the Iberian Peninsula to Islam, severely restricting the reach both of the Byzantine Empire and of its church. Christian missionary activity directed from the capital of Constantinople did not lead to a lasting expansion of the formal link between the church and the Byzantine emperor, since areas outside the Byzantine Empire's political and military control set up their own distinct churches, as in the case of Bulgaria in 919.
Justinian I, who became emperor in 527, recognized the patriarchs of Rome, Constantinople, Alexandria, Antioch, and Jerusalem as the supreme authorities in the state-sponsored Chalcedonian church apparatus (see the Pentarchy). However, Justinian claimed "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".[8][9]
In Justinian's day, the Christian church was not entirely under the emperor's control even in the East: the Oriental Orthodox Churches had seceded, having rejected the Council of Chalcedon in 451, and called the adherents of the imperially-recognized church "Melkites", from Syriac malkâniya ("imperial").[10][11] In Western Europe, Christianity was mostly subject to the laws and customs of nations that owed no allegiance to the emperor in Constantinople.[12] While Eastern-born popes appointed or at least confirmed by the emperor continued to be loyal to him as their political lord, they refused to accept his authority in religious matters,[13] or the authority of such a council as the imperially convoked Council of Hieria of 754. Pope Gregory III (731–741) was the last Bishop of Rome to ask the Byzantine ruler to ratify his election.[14][15] With the crowning of Charlemagne by Pope Leo III on 25 December 800 as Imperator Romanorum, the political split between East and West became irrevocable. Spiritually, Chalcedonian Christianity persisted, at least in theory, as a unified entity until the Great Schism and its formal division with the mutual excommunication in 1054 of Rome and Constantinople. The empire finally collapsed with the Fall of Constantinople to the Islamic Ottoman Turks in 1453.[16]
The obliteration of the empire's boundaries by Germanic peoples and an outburst of missionary activity among these peoples, who had no direct links with the empire, and among Pictic and Celtic peoples who had never been part of the Roman Empire, fostered the idea of a universal church free from association with a particular state.[17] On the contrary, "in the East Roman or Byzantine view, when the Roman Empire became Christian, the perfect world order willed by God had been achieved: one universal empire was sovereign, and coterminous with it was the one universal church";[18] and the church came, by the time of the demise of the Byzantine Empire in 1453, to merge psychologically with it to the extent that its bishops had difficulty in thinking of Nicene Christianity without an emperor.[b][21]
The legacy of the idea of a universal church carries on in today's Catholic Church, Eastern Orthodox Church, Oriental Orthodox Churches, and the Church of the East. Many other churches, such as the Anglican Communion, claim succession to this universal church.
Legacy[edit]
Following the schism between the Eastern and Western churches, various emperors sought at times but without success to reunite Christendom, invoking the notion of Christian unity between East and West in an attempt to obtain assistance from the pope and Western Europe against the Muslims who were gradually conquering the empire's territory. But the period of the Western Crusades against the Muslims had passed before even the first of the two reunion councils was held.
Even when persecuted by the emperor, the Eastern Church, George Pachymeres said, "counted the days until they should be rid not of their emperor (for they could no more live without an emperor than a body without a heart), but of their current misfortunes".[88] The church had come to merge psychologically in the minds of the Eastern bishops with the empire to such an extent that they had difficulty in thinking of Christianity without an emperor.[21]
In Western Europe, on the other hand, the idea of a universal church linked to the Emperor of Constantinople was replaced by that in which the Roman see was supreme.[e] "Membership in a universal church replaced citizenship in a universal empire. Across Europe, from Italy to Ireland, a new society centered on Christianity was forming."[90]
The Western Church came to emphasize the term Catholic in its identity, an assertion of universality, while the Eastern Church came to emphasize the term Orthodox in its identity, an assertion of holding to the true teachings of Jesus. Both churches claim to be the unique continuation of the previously united state-sanctioned Chalcedonian and Nicene Church, whose core doctrinal formulations have been retained also by many of the churches that emerged from the Protestant Reformation, including Lutheranism and Anglicanism.