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CONSTANTINIANISM is a policy establishing a particular Christian church as the religion of the state, also known as Caesaropapism. Formulated originally by the Roman emperor Constantine I, the Great (d. 337), it was continued in the Byzantine Empire (until 1453), the Frankish kingdom, the Holy Roman Empire (9621806), and numerous states of Europe, being modified in most states since the Protestant Reformation but persisting in some even today. According to this policy, state and church should form a close alliance so as to achieve mutual objectives.

Constantinianism Conceived

Following his "conversion" in 312, Constantine proceeded by stages to establish Christianity as the sole religion of the empire. From 312 to 320 he tolerated paganism but he elevated the standing of Christianity with increasing vigor. From 320 to 330 he thrust the organization of the church into the foreground and directed a frontal attack on polytheism. From 330 to 337, after moving the capital from Rome to Byzantium, he waged an open war on the old religion.

Constantine, whatever the exact nature of his conversion, believed that the supreme God whom Christians worshiped had given him the victory at the Milvian Bridge and dominion over the empire. He hoped that by doing God's will he would obtain further prosperity for himself and his subjects and feared that if he offended God he would be cast down from power and pull the empire down with him. In a letter to an official charged with responsibility for healing the Donatist schism, the emperor confessed he would feel secure "only when I see all venerating the most holy God in the proper cult of the catholic religion with harmonious brotherhood of worship." This concern for right worship prompted him to seek not merely the establishment of Christianity but the conservation of a united and orthodox Christianity. Bitterly offended by division among Christians, he felt duty-bound to impose unity, first in the Donatist controversy and then in the Arian. To resolve the latter, he summoned a universal council representing the whole church to meet at Nicaea, and presided over it himself. In an opening address he deplored the internecine strife in the church as a disaster greater than war or invasion. During the crucial part of the debate, he himself chaired and took an active part in guiding the proceedings. He used his imperial presence to secure an inclusive formula with which all except ardent Arians could agree, proposing the phrase "of one essence" (homoousios) to express the Son's relation to the Father.

Though Constantine's peacemaking efforts within the church turned out rather badly both for his and later generations, he put in motion a program that would eventually secure the triumph of Christianity over its competitors. When his co-emperor Licinius turned sour toward Christianity and backed away from the tolerance guaranteed by the Edict of Milan (313), Constantine initiated against him a virtual crusade culminating in his defeat and death in 324. Thenceforth, as Constantine once remarked in a speech to bishops he was entertaining, he considered himself "a bishop established by God of those outside [the church]." He thought of himself, too, as a "thirteenth apostle." If he did not undertake to promote missionary work outside the empire, he did so within its boundaries. He grew increasingly impatient with the unwillingness of his subjects to accept the Christian faith until finally, in 330, exasperated with the tenacious grip of paganism on old Rome, he established a new Christian capital at Byzantium. Thereafter he held back nothing, razing and looting temples and lavishing public monies on the churches, forcing pagans to return property confiscated from Christians under Licinius, building churches of great splendor in important cities, and enticing soldiers and public officials with lavish favors. His successors, Julian (361363) excepted, followed suit, and by the time of Justinian (527565), intolerance toward non-Christians had become a public virtue.

Constantinianism Controverted

Constantinianism was never seriously contested in the Byzantine Empire, but it has been in other nations, especially in the West. The so-called Donation of Constantine, a spurious document composed between 752 and 778 in the Carolingian (Frankish) kingdom, inaugurated a long history of debate over relations between church and state with strong advocacy of the superiority of popes to princes by grant of Constantine himself. Charlemagne, king of the Franks from 778 to 814, and his successors operated on the Constantinian model, aiding the church in its evangelism but using it to achieve royal aims and freely interfering in ecclesiastical affairs. Their practice of lay investiture, secular rulers handing symbols of office to the clergy at their installation, however, touched off a fierce battle with the papacy on which compromise was not achieved until 1122. Subsequently, Innocent III during his years as pope (11981216) stood Constantinianism on its head by liberal interference in matters of state in the Holy Roman Empire and virtually every nation in Europe.

The strongest objections to Constantinianism, however, have been voiced by sects that have suffered from its emphasis on uniformity. The ancient Donatists, ruing their request for imperial involvement in ecclesiastical disputes, soon advocated separation of church and state. So too did some medieval sects. The most persistent and consistent voice against Constantinianism, however, has come from the so-called free churches that emerged at the time of the Protestant Reformation in the sixteenth century and after. Many of these, especially Anabaptists and Baptists, have denounced the alliance of church and state that Constantine effected as a "fall" of the church, resulting not only in religious intolerance and persecution but also in an adulteration of Christianity. According to a Hutterite chronicle, this well-intended alliance is how "the disease of craftiness, which creeps about in darkness, and the corruption which perverted at high noon, [was] introduced by violence" and "the Cross was conquered and forged to the sword." In opposition to Constantinianism, the free churches espoused voluntary association in congregations and separation of church and state. "Gathered churches" composed of "regenerate members," and not the state or its magistrates, would, by this plan, exercise discipline in doctrine and behavior over their constituents. Although government has a legitimate role to play, the free churches further stated, it should restrict its activities to the civil realm and leave religion to the churches. God alone is Lord over the human conscience in religious matters.

See Also

Anabaptism; Arianism; Constantine; Donatism; Heresy, article on Christian Concepts; Innocent III; Reformation.


Constantine's Christian intentions have been the subject of many recent books. Most helpful in interpreting his policy are Andrew Alföldi's The Conversion of Constantine and Pagan Rome, translated by Harold Mattingly (Oxford, 1948), and A. H. M. Jones's Constantine and the Conversion of Europe (London, 1948). A critical assessment of Constantinianism can be found in Hermann Dörries's Constantine and Religious Liberty, translated by Roland H. Bainton (New Haven, 1960).

E. Glenn Hinson (1987)

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