The coronation of Charlemagne by Pope Leo III on Christmas Day in the year 800 CE consolidated minor changes in European and Christian history that had been happening since Constantine into a significant instance that would reverberate until, arguably, the end of Christendom sometime within the collapse of the European colonial systems. That instance was not the union of, but rather the desired harmonization of, the vast social systems of church and state throughout the fragments of the Western Roman Empire and its environs.
As with any other human moment, the coronation of Charlemagne proceeded from mixed motives and proceeded into clouded actions. This is not to say that nothing clear occurred, but it is to say that what happened and why it happened is grounded in complexity. For example, the rise of the Roman papacy to the position where it could even crown a monarch had been developing since the martyrdom of Peter and Paul in the very first century of Christianity.
This occurred not simply because Rome was the power-hungry see in the seat of the Empire but, more complexly, because it was flattered into prominence. The scriptural prominence of Rome became its status as the seat of apostolic succession which became, in turn, its place as the spiritual center of Roman Christianity which then became its authority, after the legalization of Christianity by Constantine, as the court of appeal for the decisions of local councils – recall here the practice of Episcopal audience, where bishops judged Imperial law as a service to the city.
Would this have made the bishop of Rome first among equals in the eyes of Imperial courts as well as Imperial churches?
Regardless, the Roman see’s position as spiritual and political center was becoming clearly established by the time the Empire collapsed, and certainly, undeniably, by the time of Gregory the Great circa 500 CE. While one can hardly say that the Bishopric of Rome ascended to control as a selfless act of love for the common people, one also cannot say that through the centralization of Rome as the heart of Western Christianity, absolutely no good was accomplished. The servant of the servants of God would, by both choice and necessity, spread Christianity throughout a crumbling European social order and of course to some degree became that order.
When Pope Leo III crowned Charlemagne, Western Christianity was ready for the marriage, both through the centralization of spiritual authority and through its own territorial expansion. But was the King of the Franks ready, for his part, to defend so much of the faith? The Islamic conquests of the period actually did recognize the distinction, conquering states without forcing conversion – still, it stopped by law the territorial expansion of Christianity that had been happening through its zealous missions.
Stopped it south and westward, that is – making Rome not the central seat of a Mediterranean Christianity but the fount of a northward-seeking Christianity centered precisely in the territory governed by the Frankish kings. Those kings were themselves experiencing a consolidation of power through the mediation of those like Charles Martel who arguably saved Europe from Islam at the battle of Tours in 732, the punctuation of a brilliant military career that, two generations before Charlemagne, both subjugated potential rival powers and aided Christian missionaries in the land.
But where did all of this go? The harmonization of church and state in Christendom meant the increased power of the church to touch all areas of life for its believers, from cradle to marriage bed to grave at the same time as the church’s theology swerved toward the sacramental – an alteration which was by no means coincidence, as grace manifested to the people became the church missiology and the arms of the Carolingian empire reached out to everyone.
But a relationship is not a merger, and intended harmony is not its actuality, as the respective powers would alternately try and succeed to trump each other and righteousness, of course, did not follow the designs of any social system. Still, the harmonization of church and state in Christendom meant a sense of direction from top to bottom which Western Civilization had not seen before and arguably would not see again.