Charlemagne and the Legacy of Christian Political Violence


With moral chaos abounding in the world today, many evangelicals wonder if the nation would be better if the church were in charge. Like the good ole days of Christendom, maybe we should return to a sword-and-shield world where state and church combine efforts.

It might serve Christians today, therefore, to be at least somewhat aware of the history of how the church has used state violence for its purposes, particularly as conversations about theonomy, magisterial Protestantism, and Christian nationalism have grown in urgency of late. To this end, Charles the Great, or Charlemagne, is one crucial figure to consider. So is his legacy of military conquest performed in the name of Christ.

Known as the grandfather of modern Europe, Charlemagne codified the partnership between the emperor and the papacy, making the papacy Christian Europe’s most powerful authority. A key feature of their partnership was Charlemagne’s use of state coercion to convert pagans to Christianity.


Christians had employed violence before Charlemagne. Once Constantine became the emperor of Rome, rogue groups of Christians began to sack pagan temples. However, these events were sporadic and independently orchestrated, and they never received the official endorsement of the church.

Augustine may have been the first Christian to advocate the use of violence to enforce Christian beliefs. Though originally reluctant to use violence, Augustine came across Jesus’s banquet parable, which he found useful for dealing with the theologically aberrant Donatists. A rich man prepares a feast. His invitees don’t come. So he tells his servants to “compel people to come in” (Luke 14:23). Augustine used this verse to justify the use of coercion to bring the Donatists back to the fold. Augustine’s appeal to the civil authorities was heeded, resulting in the outlawing and persecution of the Donatists. Augustine remarked,

The Church persecutes by loving; they [the Donatists] persecute by raging. The Church persecutes in order to correct; they persecute in order to destroy. The Church persecutes in order to call back from error; they persecute in order to cast down into error. The Church, finally, persecutes and lays hold of enemies until they collapse in their vanity so that they may grow in the truth. They return evil for good because we have at heart their eternal well-being, while they try to take from us even our temporal well-being.[1]

Notice Augustine’s goals for the use of coercive force: “to correct”; “to call be from error”; for “eternal well-being.” In other words, he sought to protect the purity of the church. In that sense, his call for violence arguably more resembled the post-Reformation wars than the religious wars against the pagans during the Middle Ages.


What Charlemagne introduced was using force to convert pagans into Christians. And Charlemagne’s use of violence to create Christians served as a model for the next thousand years.

Charlemagne and his brother, Carloman, became joint rulers of the Franks after their father’s death in 771 AD. However, Carloman died the same year he was crowned, and Charlemagne became the sole Frankish king. Without wasting any time after his coronation, Charlemagne led his army to war with the pagan Saxons of the north.

The Saxon wars began in 772 A.D. As his first military move, Charlemagne desecrated the Irminsul, a pagan tree used for the worship of Saxon gods. This act struck at the heart of his enemy’s pagan ideology. From there, Charlemagne’s victories were many. In the face of success, he became increasingly convinced that God’s favor was on him. To pay homage, Charlemagne forced prisoners of war to confess Christ and be baptized. The Royal Frankish Annals depict these pagan “conversions”:

There they all surrendered their fatherland (patria) by a pledge into their [the Franks”] hands, promised to be Christians, and subdued themselves to the rule of the lord king Charles and of the Franks. . . They came with their wives and children, a multitude without number, and were baptized and gave hostages, as many as the king asked for. Charlemagne viewed the Saxons as lost souls who needed to be “compelled to come in.”[2]

He regarded his military crusades as his Christian duty and the duty of the Franks.

Saxony would eventually be “converted” by being conquered in 804 A.D., after eighteen bloody campaigns that saw thousands of deaths and thousands more displaced.


The Catholic Church approved of Charlemagne’s tactics. His military endeavors were heavily influenced by clergy like Archbishop Lullus of Mainz, a Frank who had dedicated his life to the ministry of Saxony. Every time that Charlemagne would leave the region, the Saxons would flare back up in rebellion. Lullus saw this and argued the only way to save the Saxons was through violence, for “these stubborn people will never convert on their own. So, we have got to force them to submit.”

During those campaigns, in 796 A.D., Charlemagne wrote to Pope Leo and affirmed his purpose in “enforcing” acceptance of Christianity. He also asked for the pope’s aid in the endeavor.

Charles, by the grace of God, King of the Franks and Lombards, and patrician of the Romans, to his holiness, Pope Leo. . . I will ever defend the most holy seat of the Holy Roman Church. For it is our part to defend the holy Church of Christ from the attacks of pagans and infidels from without and within to enforce the acceptance of the Catholic faith. It is your part, most holy father, to aid us in the good fight by raising your hands to God as Moses did, so that by your intercession the Christian people under the leadership of God may always and everywhere have the victory over the enemies of His holy name, and the name of our Lord Jesus Christ may be glorified throughout the world.

The correspondence outlines a division of labor for advancing and protecting Christianity. Charlemagne was the sword and shield of the Christian faith, while the pope was its intercessor. The former concerned himself with the temporal domain, while the latter oversaw the ecclesial.

Yet these lines, already a little blurry, would become more so when, on Christmas Day 800 A.D., the pope crowned Charlemagne as emperor of the Holy Roman Empire. By overseeing Charlemagne’s coronation, the pope foregrounded his authority over the empire (temporal). Similarly, Charlemagne’s title as emperor of the Holy Roman Empire affirmed his duty to protect and advance Christianity (ecclesial).


Charlemagne believed he was doing the Lord’s work by “preaching with tongues of iron.”[3] In the name of Christ, he conquered pagans and forced them to be baptized, making them members of the Catholic Church. Though not necessarily his intention, he established a precedent for religious violence and warfare. Again and again, Christian Europe would use him as an example of how to deal with its non-Christian neighbors. Future generations of governments were eager to replicate his legacy.

The First Crusade

In the Middle Ages, for instance, Christendom found itself pressured on multiple fronts. This was nowhere more felt than in the Byzantine Empire, where Turks, recently converted to Islam, raged against Christians and Arabs alike. After capturing Jerusalem, nomadic Turkish tribes moved to set up a capital city just 100 miles south of Constantinople, the Byzantine capital. Unable to deal with the Turkish invaders on his own, Byzantine emperor Alexius Comnenus wrote to Pope Urban II for aid. Alexius could not have hoped for a better outcome.

After receiving Alexius’s letter, Urban called for the Council of Clermont in 1095. There he would present a speech that would come to be regarded as one of the most important speeches in European history. With an immense crowd listening, Urban implored Christian knights to take up the sword against the Turkish invaders and Muslims more generally. He motivated them by graphically detailing the torture, rape, and murder of their fellow Christian brothers and sisters in and around the Byzantine Empire. The Pope then turned to the example of Charlemagne to inspire his audience. He said to them:

Let the deeds of your ancestors move you and incite your minds to manly achievements; the glory and greatness of king Charles the Great (Charlemagne), and his son Louis, and of your other kings who have destroyed the kingdom of the pagans (Saxons) and have extended in these lands the territory of the holy Church. Let the holy sepulchre of the Lord our Saviour, which is possessed by unclean nations, especially incite you, and the holy places which are now treated with ignominy and irreverently polluted with their filthiness. Oh, most valiant soldiers and descendants of invincible ancestors, be not degenerate, but recall the valor of your progenitors.

The pope knew Charlemagne’s reputation continued to loom large in Christian Europe. Therefore, he made him an exemplar for the crusaders. Between 60,000 and 100,000 men then responded to the pope’s call. Following Urban’s speech, the crowd erupted into what would become the crusaders’ battle cry: “Deus le vult!” or “God wills it.” They also decided at that time that crusaders would wear a cross on their foreheads and shield.

The first crusade to defend the brethren and reclaim lost territory for the Church was launched in 1096 A.D. It was quickly proven more successful than Alexius or Urban originally intended. After making short work of the Turks near Constantinople, crusaders went on without order to Jerusalem, sacking and reclaiming it for the Church. With the Holy Land in hand, they established the Crusader States, which were army-controlled territories won through battle. Unfortunately for the Church’s army, the Muslims soon retook these territories, propagating many more Church-sponsored campaigns to recapture the Holy Land.

Christendom now had the military force to enforce its theology of Christ Jesus. After the first crusade, monastic military orders emerged dedicated to killing pagans and propagating the word of Christ: knights templar, knights hospitaller, knights order of the Holy Sepulchre, order of Saint Lazarus, and the Teutonic Knights. These orders popped up all over the Middle East, Hispania, and the Baltics. All shared a strict code of conduct to follow the teaching of Christ and to strike down his enemies.

Examples like that of the first crusade are aplenty. Like Charlemagne, the crusading Church of the Middle Ages was comfortable using its might and mane to spread the gospel. Therefore, they leaned on his example to justify doing so.

Spanish Reconquista

Another example: Charlemagne had been defeated when attempting to rescue the Iberian Peninsula from Islam. Later Christian forces followed in his footsteps by seeking to retake it in what historians call the Spanish Reconquista, which lasted until the late fifteenth century. Medieval Spain became a scene of constant warfare between the followers of Christ and Mohammed. Christians brutally slaughtered the Muslims in the battle of Las Navas de Tolosa in 1212.[4] By 1250, almost all of Iberia was under the rule of Christians except for the Muslim kingdom of Granada, which held out until 1492.

Christian kingdoms did not show any mercy. At the end of the wars, Spain’s Muslim population was estimated to be between 500,000 and 600,000. Before the wars, a few hundred years earlier, the Muslim population is estimated at around 5.5 million.[5]

Victory led to the forced conversion of both Muslims and Jews on multiple occasions: it was enacted by the Crown of Castile in 1500–1502, in Navarre in 1515–1516, and by the Crown of Aragon in 1523–1526.[6] The Spanish Inquisition[7] upheld the same policies as the Spanish Reconquista, forcing all Muslims and Jews to convert to Catholicism. Those who refused to convert were brutally tortured and killed.

Teutonic Wars

The Teutonic wars were the conquest and forced conversion of the Grand Duchy of Lithuania by the Teutonic knights and other European forces. They lasted from 1230 to 1411. The Teutonic knights were especially brutal to their pagan neighbors. One historian referred to how the knights dealt with those who refused to convert—“Roasting captured brethren alive in their armor, like chestnuts, before the shrine of a local god.”[8] The knights spared no one in their quest to convert the people. Taking after Charlemagne, they forced conversion on pagans before allowing them to return to a semi-normal life.

Ultimately, the church’s use of force became less about propagating the gospel and more about conquest and glory. Charlemagne’s means were saddled to vain ends.


What relevance does Charlemagne’s example have for today’s conversations about theonomy and Christian nationalism?

Nearly everyone would count Charlemagne’s example as extreme. Even the most ardent theonomist or Christian nationalist will remark, “Of course, we cannot convert people by the threat of the sword! That’s ridiculous.” So why recount the history at all?

There are two possible answers to that question. Those who advocate for some version of theonomy should beware of perversions, and they should beware of precedents.

In terms of perversions, time and time again, church power becomes abusive and dangerous when it employs the sword to enforce its rule. Charlemagne’s religious wars were not the first or last time the violence was used for Christian ends. In the 1096 crusade mentioned above was the first of nine. And many more examples could be mentioned. When the church possesses coercive power, it invariably becomes warped and corrupted. Those who advocate for some version of theonomy should ask themselves, “How might the systems of governance I’m promoting be abused?” Because they will be abused.

In terms of precedents, Charlemagne serves as a possible lesson in the telos of Constantinianism. Augustine used violence to protect the purity and unity of the church, Charlemagne for the conversion of pagans. Yet are these two things that different categorically? Both rely on the sword for the advance of Christ’s kingdom. What if we were to lower the stakes to something like a religious tax on unbelievers or a religious test for office holders? Both are clearly less violent or forceful than holding a sword to someone’s throat. Yet isn’t the difference now one of degrees? Aren’t we still relying on coercion for a spiritual result? Both tax and test remain qualitatively distinct from the ordinary means of grace. The apostles relied on preaching and prayer (Acts 6:4; 2 Cor. 4:2). Their weapons of warfare were not of the flesh (2 Cor. 10:4).

By the same token, theonomists today argue that the civil laws of Israel establish a precedent for us, whether to be applied precisely (“Reconstructionists”) or with adjustments for time and place (“General Equity”). If that’s the case, wouldn’t Israel’s use of holy war in conquering the land of Canaan establish a viable precedent for us, too? If not, why not?

Perhaps it’s time to focus instead on building the heavenly city promised in the Revelation of John.

* * * * *

[1] Augustine Hippo Saint, Bishop of, S. Aureli Augustini Hipponiensis Episcopi Epistulae : Pars III. Ep. CXXIV-CLXXXIV A (Austria: F. Tempsky, 1904), 23.24-26.

[2] Bernhard W Scholz and Barbara Rogers, Carolingian Chronicles: Royal Frankish Annals and Nithard’s Histories (U. of Mich. P, 1970), 155.

[3] Oliver J. Thatcher and Edgar Holmes McNeal, A Source Book for Mediæval History Selected Documents Illustrating the History of Europe in the Middle Age (Project Gutenberg, n.d.), 42707.

[4] Martín Alvira Cabrer, Las Navas de Tolosa 1212 (Madrid: Silex, 2012).

[5] L P Harvey, “Blood and Faith: The Purging of Muslim Spain, 1492–1614 By Matthew Carr,” Journal of Islamic Studies (Oxford, England) 30, 30, 1 (January 1, 2019): 111–14.

[6] L P Harvey, “Blood and Faith: The Purging of Muslim Spain, 1492–1614 By Matthew Carr,” Journal of Islamic Studies (Oxford, England) 30, 30, 1 (January 1, 2019): 111–14.

[7] The Spanish Inquisition (1478–1834) was a judicial institution ostensibly established to combat heresy in Spain. In practice, the Spanish Inquisition served to consolidate power in the monarchy of the newly unified Spanish kingdom, but it achieved that end through infamously brutal methods. Rafael Sabatini, Torquemada and the Spanish Inquisition: A History (Stanley Paul & Co, 1913).

[8] The Teutonic Knights: The History and Legacy of the Catholic Church’s Most Famous Military Order (Charles River Editors, n.d.), 11.

Dustin Asbury

Dustin Asbury is an associate pastor of Haven Baptist Church in Kansas City, Kansas while also pursuing a PhD in Historical Theology with an emphasis on the Medieval Church.

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