No, then yes, then no.
Do not suppose that I have come to bring peace to the earth. I did not come to bring peace, but a sword. (Matthew 10:34)
Conversion by the sword is forced conversion using a physical threat and/or the threat of death: convert or die. From our modern perspective, this is a form of persecution, and when it was happening, and it did happen, many other types of persecution were also taking place.
Christianity didn’t start that way. The majority of historians agree that the thirteenth century was a turning point. From the eleventh (after 1050) to the thirteenth (c.1250) centuries, things changed across the board. Church and society became more intolerant and more authoritarian and more willing to persecute “outsiders.” This is an accepted fact among historians.
There was drastic change in almost every realm of life. The crusades began, leaders left, the church became militarized, trade opened to the East, a cash economy developed, urban values rose that replaced and challenged previous values, literacy rose and the literate sometimes used their influence in support of persecution of minorities, the law changed, social structure changed, social ideals changed: life, people, values and goals, all began moving toward the secular and the secular State and away from the feudal and religious. Without a doubt this “dislocation” disoriented many.
The growth of secular political power, and its centralization, were the driving forces behind the development of persecution as a tool of enforcement, with the church, which was also becoming a centralized power, playing a significant role, but not the leading one. 
Nevertheless, there are egregious examples of conversion by the sword being used by the church of the Middle Ages involving Muslims, the Jews, the Albigensian and Northern Crusades, Inquisition, and the forced conversion of natives during colonization.
Then the church stopped. The secular State did not.
Throughout its first millennium, Christianity spread almost exclusively by non-violent missionary activity. There are hundreds of examples: the Gregorian mission to the Anglo-Saxons, the mission to the Picts at Iona by Columba, St. Boniface and the Saxons  to mention a few. Any violence involved was directed at the missionaries, not by them. For centuries, disagreement among Christians was settled by Councils—not swords.
The Christian church might claim to have no comparable doctrine to jihad (which is mainly for self-defense in Islam) and did not, as a rule, practice conversion by the sword or even use violence in self-defense for centuries. (That is not to say there are no alleged acts of violence by mobs or locals acting on their own without church approval.)
But such claim by the church does not mean that the Biblical texts are innocent from inciting rape and murder.
The false pretentious conviction that Christianity was incompatible with the willful shedding of blood was maintained and defended by eminent individuals like Tertullian of Carthage, Hippolytus of Rome, and Origen of Palestine and Egypt, such false pretentious conviction would be the otherwise if they had the might and power at the time, which later the willful shedding of blood occurred.
The false pretentious conviction that Christianity was incompatible with the willful shedding of blood was a widely held principle that was believed and acted on in the Churches up and down Christendom.
Which was demonstrated few centuries later in the form of mass slaughtering of the natives and aboriginals of New Zealand, Australia, Canada, United States, the Sub-Indian continent, and many other African, Arabic, and Islamic countries.
Then things began to change.
- Power and Personal Gain
Between the eleventh and thirteenth centuries, a new class of middle-management functionaries in both church and state appeared: clerics and courtiers. Their primary focus revolved around extending the political power of their masters in order to consolidate their own position and undermine their rivals.
It was this group of people who proclaimed the dangers of minority groups; and it was this group who recommended the remedies involving persecution and the sword.
- The Literati wrote against Minorities
The role of the literati was central.
… However, the tremendous extension of the power and influence of the literate is described, the development of persecution in all its forms was part of it, and therefore inseparable from the great and positive achievement with which it is also associated.
- Power Was Centralized and The Law Changed
In the early medieval period (800s), legal codes dealt directly with the individual offender. Punishment for criminal activity was generally resolved between the parties involved and, in the Germanic manner, often resulted in some form of monetary payment.
Order was maintained by the community, family, and clan.
When the emerging nation states of Western Europe, and the papacy, began to centralize their power, taking more and more of it for themselves and away from others, they developed a system which included an apparatus of specialized groups such as police forces and courts of inquisition used for the enforcement of their new power.
Order became imposed from above.
This transition had severe repercussions for minorities.
- Victimless Crimes Were Invented
The transition from a passive to a persecuting society can be seen in the increase in both secular and papal legislation aimed at minorities. Medieval rulers began to assert their fledgling authority by creating victimless crimes which were, in essence, crimes against society, state, and morality. These crimes were actively sought out and the alleged criminals were punished: there was no individual offended party able to accept restitution or recompense.
By 1208, there was increasingly severe and wide-ranging law against ‘heretics.’ In 1226, Louis VIII barred heretics from public office and confiscated their lands. Frederick II laid down draconian measures for his Empire, and in 1233, Jaime the Conqueror of Aragon moved remorselessly against the “enemies of God” with the force of law.
By the 1300s, there was a formidable array of legal sanctions being used against minorities of all types.
By 1478, King Ferdinand of Spain became the role model for Machiavelli’s “The Prince.” Blackmailing the Pope, (who tried to shut down the Inquisition in Spain because it used torture), Ferdinand took control of the Spanish Inquisition for the crown allowing him the full weight of Law and Church combined to unify his new kingdom and eliminate all minorities.
- The Fourth Lateran council of 1215
Within the church, the Forth Lateran Council of 1215 laid down the mechanism of persecution, and created a range of sanctions, which proved to be adaptable to a wide variety of victims. The sanctions originally designed for heretics, were easily adapted for Jews, Muslims, “sodomites”, prostitutes, and any other minority groups that did not fit in.
In later centuries, targets multiplied. In 16th Century Germany, beggars, gypsies, spendthrifts, discharged soldiers, and others, were made vulnerable by being classified as outsiders; the witch hunts of the sixteenth and seventeenth centuries were persecutions based on gender; and the totalitarianism of the twentieth century can be seen as an outgrowth of the mindset that began in the Middle Ages toward minorities and outsiders.
The Fourth Lateran Council included a regulation that Jews must wear a special dress to distinguish them from Christians: a yellow badge.
Persecution began in the Middle Ages, and the Enlightenment blamed the church. It seemed simple enough. But the decentralization of the church, the closing of courts of inquisition, and the elimination of church soldiers, did not stop the persecution and abuses of minorities in European societies and their colonial offshoots.
Persecution has continued to be used by various State authorities throughout the twentieth century, and on into the twenty-first, to displace popular institutions and to interfere directly in every aspect of daily life. The modern state has acquired a capacity to persecute beyond the dreams of even the most ambitious medieval ruler. Authority is still imposed from the top-down by specialized groups with power from the State.
Since World War II, society has begun recognizing the need for some basic changes necessary to cope with this. There has been a universal move to affirm the inalienable nature of human rights. Discussion of the nature of true democracy is being reopened. There has been a recognition of the necessity of the rule of law to be equally applied for “civilization” to exist.
Arbitrary arrests, imprisonment without trial, torture, invasion of privacy by the State, are being rejected on moral grounds, but also on practical ones: economies suffer when persecution is allowed. People suffer. These are the practices that reflect a persecuting society.
Minorities are the most vulnerable, but no one is safe when a centralized power of any kind—religious or secular—misuses its power to further its position at the expense of its people.
Conversion by the sword seems impossible to comprehend. It’s more than just hard to imagine, for the more we learn about it, the more it becomes a true conundrum. The Enlightenment thinkers blamed persecution on those with religious convictions which, it is now universally acknowledged, inspired the noblest minds and highest achievements of Western history.
How can both those things be true?
Since history now shows violence continued long after the church lost its enforcers and its position as a centralized power, modern scholars have looked elsewhere for explanation, primarily blaming the violence natural to the ‘common’ man of the Middle Ages instead of the church. But how is it the ‘powers that were’ did what the masses wanted?
As it turns out, these a priori positions are not well founded in fact. Instead, they are largely a result of hatred of the church and the Enlightenment belief that liberty and progress go hand in hand.
The twentieth century has pretty much put paid to the Enlightenment belief that “barbarous” societies will inevitably give way to “civilization,” and also made it clear that the removal of the church as a centralized power did not stop persecution.
In the twenty-first century, the question of causality remains open.
“… the honorable and proper struggle of serious historians of all religious persuasions and none, is to achieve a sympathetic comprehension of a distant civilization and its institutions. … to sedulously strive, with Spinoza, not to ridicule men’s actions, or bewail them, or despise them, but to understand.” R.I.Moore
Let us strive to understand.
Formerly a persecuted and voluntary community, the Church after Constantine enjoyed, not just relief, but eventually, favor. Later Emperors either tolerated or embraced Christianity, which continued to grow in popularity, until in 380 AD Emperor Theodosius I made it the official state religion of the Roman Empire.
This new social situation precipitated fundamental shifts in Christian ethical thinking. The transition from early Christian pacifism to the later Christian embrace of soldiering as a proper Christian duty concretely epitomizes this. However, this shift did not include embracing conversion by the sword.
Theodosius’ Edict of Thessalonica was designed as the final word on controversies within the early church. With it, the old pagan religions were now suppressed. Temples were destroyed, monetary support withdrawn, and various other repressive measures were taken, but there were no mass murders of pagans. Christian leaders did not support conversion by the sword. Ambrose’s response to the Massacre at Thessalonica is sufficient proof. Theodosius’ killed 7000 pagans who rioted over a local power struggle. Ambrose was appalled and refused to even see him until he repented and made a law to prevent it ever happening again.
Ambrose refusing to allow Theodosius to enter the church until he repented of the deaths in Thessalonica.
The Donatist Controversy
Another example sometimes used to claim Roman Christians supported violence to convert others is actually somewhat of a gray area: the conflict was an internal one, between Christians, the violent coercion was done by the Roman government, and there was cause for action, which could mean this is more about ‘policing’ than converting.
It started in the last decade of the 3rd century when Emperor Diocletian ordered persecution of Christians. Some resisted and were martyred, but some renounced Christianity and were spared. What was the church to do about those who had recanted then wanted to return?
Donatists refused to accept them back as clergy and remained resentful toward the Roman government. Catholics wanted to wipe the slate clean and accommodate the government. Attempts to reconcile, made by Constantine, a number of Popes and councils, and respected figures such as Augustine of Hippo, all failed. Donatists fomented protests and street violence, refused compromise, attacked random Catholics without warning, doing serious and unprovoked bodily harm to people who were guilty of nothing but being on the other side of the argument.
After decades of violence and failure, Augustine of Hippo reversed himself and his previous teachings against the use of force and instead wrote a justification for using force to “educate” the Donatists. Augustine was the bishop, and his people’s safety was his legitimate concern: was his response justifiable, or does it qualify as an example of using the sword for religious conversion?
Whichever it was, the Roman government ran with it. The Donatists were then persecuted to such a degree that Augustine later protested their treatment.
The first real instance of conversion by the sword might be what took place at the Massacre of Verden in the year 782.
Did the ‘Massacre of Verden’ actually happen with 4500 people being killed in a single day? Was the Carolingian ruler (and later Holy Roman Emperor) justified in his actions? Or was this a brutal act of ethnic cleansing that has left a terrible mark on the man who is credited with re-establishing Western Europe after the fall of the Roman Empire?
Charlemagne’s reign (768-814) was one of almost continuous warfare, but his longest and most difficult war was against the Saxons whom he fought for thirty years. His father had fought the Saxons. His grandfather had fought the Saxons. The Saxons had raided Frankish borders for a century. Warfare between these two groups was ferocious, as Charlemagne—and his enemies—could field armies in the tens of thousands.
The events of 782 started when Widukind, the Saxon leader, persuaded a group of Saxons who had submitted to Charlemagne, to rebel. They went to battle with a Frankish army and annihilated it, killing two of the King’s chief lieutenants, some of the king’s closest companions and counsellors, his tent-sharers, and the men of his hall. By the standards of the day, a good lord could not fail to respond. Charlemagne responded. He gathered his forces, returned to Saxony, and unleashed his massacre at Verden, giving the captured rebels the option, convert or die, allegedly killing 4500 people in one day.
Was it justified? Was it conversion by the sword?
Today you will find that this topic gets a wide range of treatment, with some books barely mentioning the events of 782, while others offer stark judgments upon it.
Charlemagne receiving the surrender of Widikund.
After Roman Empire fell, Jews and Gentiles mostly lived at peace alongside each other. Any forced conversion of the Jews generally took place during riots by mobs, local leaders and lower-level clergy without support of church leaders.
Up until 1244, the church was guided by the teachings of Augustine of Hippo (354 AD-430 AD) concerning the Jews. Augustine had rejected those who argued the Jews should be killed, or forcibly converted, saying Jews should be allowed to live in Christian societies and practice Judaism without interference because of their reverence for the Old Testament. This became the official policy of the popes. In 590, Pope Gregory I defended the Jews against forced conversion. In 828, Gregory IV did the same.
But it was Archbishops and Bishops who had jurisdiction on the local level, and the degree of tolerance or persecution depended on them more than on the Pope. Their record is mixed. There were Bishops who discriminated against Jews. There were also Bishops such as Rudiger Huzmann, Bishop of Speyer, (1084), Johann von Kraichgau I, (1095), Archbishop Ruthard, Bishop Adalbert, and Archbishop Hermann III, (aided by unnamed Christian peasants), who risked their lives to protect the Jewish people of their towns. None of them practiced conversion by the sword.
It’s important not to forget that before the thirteenth century, Jews were sometimes treated very badly, even if that treatment did not have official sanction. They were supposed to be under the jurisdiction and protection of the secular rulers. In reality, it was the kings and princes who expelled the Jews from their lands, usually for economic and political reasons.
Yet the majority of historians agree that the thirteenth century was a turning point in Jewish-Church relations.
In the words of Hebrew University historian Benzion Dinur, from 1244 on, the state and the Church would “consider the Jews as people of no religion (benei bli dat) who have no place in the Christian world.”
Conversion by the sword? Let the reader decide.
During Christianity’s first millennium on the European continent, there are three alleged forced conversions of the Jews.
- The first is in 224, but no one is sure exactly where, or what took place, or by whom it was perpetrated, as there are no known details or records. It is impossible to verify as more than legend.
- The consensus of modern historians concerning the supposed forced conversions under the Merovingians in 592 is that they were political.
- In 1010, in Limoges, it is alleged that Bishop Alduin gave Jews the option of baptism or exile. The story goes that the Jews responded to this threat by sending an emissary, Jacob bar Yukutiel, to the Pope. The Pope responded by sending an envoy to Alduin with a papal order “not to kill, injure or rob Jews, nor to deprive them of their religion.”
The Jews in Visigoth Spain
During the 7th and 8th centuries, Iberia (what is now Spain and Portugal) was a divided kingdom ruled by the Catholic Visigoths. Historical material is hard to come by, and what there is, is mostly from the Councils, which give a record of official rulings but no indication how—or if—those rulings were implemented. 
The Council’s records indicate Jews who converted to Christianity then ‘relapsed’ back into Judaism—(the “relapsi”)— were a preoccupation of the Councils in the years 506, 633, 638, 654, 655, 681 and 693. Baptism in one way or another was ordered four times (in 589, 612, 638 and 681). However, on the whole these conversion efforts were unsuccessful. Jews were pressured, and threatened, and exiled, but not converted by the sword. It was a dire choice, but many did choose to leave, and were allowed to do so.
Christianity certainly spread by military might, the sword or whatever was the weapon of the day. It was how Peter the Great Christianized Russia. It was how the pagans of Europe were Christianized. As well as the Natives of the Americas. Backing up to the early Middle Ages, after Constantine legalized Christianity and popes anathematized other religions, Christianity burned books of non-Christians as well as heretics, and fed the authors and their followers to the lions. Christians destroyed temples and statues, forbidding anyone anywhere to believe anything other than orthodox Christianity as embraced by Eusebius, Bishop of Caesarea, friend of Constantine.
In Russia, Christianization was a military project. Our ruler Vladimir the Great and his men, according to old chronicles, diligently used both fire and sword in order to bring God’s word to Kiev and Novgorod, the two main centers of his Rus kingdom.
Doing the Lord’s work seemed to be instrumental for him in getting rid of the old tribal aristocracy. After he put some two dozens of his scions and other close family as heads of different fiefdoms in the provinces, any mentions of top aristocrats not related to Rurikids are absent in our chronicles.
Luckily, the proselytizing zeal among Rus rulers waned after Vladimir’s death forever. Christendom long remained the domain of the ruling class, and only during the rule of the Golden Horde, the Christian faith started to gradually supplant old pagan traditions among Rus and Turkic peasants.
Below, a modern artist’s vision of Vladimir the Great taking a paganic oath at his accession to the throne in Kiev.
Just like his great colleague and namesake Vladimir Putin, the duke solemnly promised to serve the idols who blessed him with power, only to later get rid of them at the time of his choosing. Russian artists who depict the conversion of Vladimir’s subjects, usually focus on the process of toppling the old gods and their ritual desecration. Men with weapon abound and Vladimir in full armor is almost never dismounted from his horse—thus sending us a message that even with God on your side, in our lands you need a lot of armed muscle for good things to happen.
President Putin, ever perceptive and perfectly PR-aware, has made an attempt to alleviate the unnecessary focus on the forcible aspect of our Christianization. A couple years back, he had a huge statue of Vladimir the Great (“Vladimir the Splendid Sun” in Russian tradition) raised a stone’s throw from his office in the Kremlin. Despite an alarmed face, this duke Vladimir holds his sword sheathed, and monk-like robes cover almost all his armor.
Yes. Not just the sword, Christianity left no stone unturned for spreading across the world. A religion that started with just a handful of people has now reached over 2.4 billion globally, almost 31% of the world population. This could not have been done with simple prayers and persuasion. Not even Jesus himself would have imagined such a massive impact of his teachings. But a lot of times, he has been reiterating the idea of spreading Christianity across the globe in the Bible.
“Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.”
And he said to them, “Go into all the world and proclaim the gospel to the whole creation.
But the initial stage of expansion was not through force; it was more of consolidation against the Roman Empire. Even in this manner, by 600 AD, 10% of the Roman Empire was Christian. Once it was declared as the official religion, it quickly took over the entire Roman empire. What is interesting to know is how it expanded in other locations. In Europe, it spread rapidly and passed down as the family religion. Force was used against Norse, Slavs, Finnish, and Baltic peoples. Apart from that, Christian wives were exported to pagan kings of the north, aiding in conversion.
In Latin America, the force was the most preferred method for converting the natives to Christianity. The conquest of South and Central America by the Spanish and Portuguese was a bloody affair. Conquistadors used Christianity as a tool of oppression and conquest throughout the continent. Natives were enslaved and often baptized against their will. In Africa, the same pattern followed but in a more organized form. Christian European nations had already established their colonies, making it a lot easier for them to spread Christianity on their subjects. The same was the case in the Indian subcontinent and even in the Korean Peninsula. Apart from forced conversion, they also demolished temples and other places of faith wherever they were in power.
There have been many champions in the Christian expansion: Charlemagne, King of the Franks in the Saxon wars, massacred over 4500 people for refusing to convert. The Rhineland massacres, the Worms massacre, followed these. In the 1400s, Spain and Portugal made the most of the end of the Islamic Rule in the region and either baptized them or massacred them.
However, the use of the sword has still not ended. Even today, in Assam, India, a militant group named Manmasi National Christian Army forces the indigenous people to convert to Christianity at gunpoint. The reasons for this and the philosophy promoting this solid drive for spreading Christianity have been very well explained in the book Evil Religions Unmasked by Eloy Colombo. It is a short but highly comprehensive read on how Abrahamic religions, including Christianity, are personifying evil in the name of religion.
Was Christianity spread through violent means?
For most of its history, yes.
Some people will try to rationalize the extreme violence committed by Christians to spready Christianity by saying ‘people in power were corrupt,’ but the answer of ‘NO’ is just blatantly wrong and that rationalization is true for literally every single ideology on the entire planet.
“Nazism was spread through violence because the people in power were corrupt” is not a justification for Nazism or its immensely profound impact on history through its violence. Likewise, justifying the suffering and oppression of millions under Christian-dominated monarchies and theocracies throughout Europe by saying “the leaders were bad” doesn’t change that the religion was spread through violent means.
In fact, I dare say that trying to justify any horrendous action that a large mass of people are complicit in or even participate in by saying ‘the leader was bad’ is an insult to anyone who suffered from that horrendous action that occurred.
Now, why one would ask this question while simultaneously linking a Wikipedia article that explicitly explains the origins of Christianity persecuting is beyond me. That article alone confirms that the answer is an obvious yes. It was spread around the world through violent means.
The fact that it had proponents who helped spread it through violence doesn’t negate the fact that the belief was spread through violent means. So the only obvious answer to this question is yes.
Now, to be fair-minded, I must say a few things:
- The fact it was spread through violence doesn’t invalidate the original message of the religion itself, it’s simply a true fact. Whether or not its true has nothing to do with how violent it was in the past.
- The origins of Christianity are relatively nonviolent ( referring here to the original pure message of Prophet Jesus son of Mary peace be upon him) and Christians were persecuted quite a bit during its early history. It was only with Constantine’s acceptance of the religion that it gained any notoriety.
- My answer is not written to try disparaging or offending any Christians, it’s written as a factual piece of information meant to answer the question: Was Christianity spread by violence?. Christianity, like it or not, was indeed spread through a combination of conquest and censorship of ‘heretics’ who did not follow the belief. This is an unavoidable fact and saying this does not and should not in anyway offend modern-day Christians.
- In America some Americans will openly admit that their ancestors committed what is essentially genocide against the Native Americans. This doesn’t make all Americans bad people. This analogy also works in regards to Christianity.