The strangest thing about religious conflicts is that some people they ever happen. They will say the Crusades were about economics and the Inquisition was a consolidation of power. They will deny that anyone fights over religion, despite the fact that the participants freely admit to fighting over religion.
Obviously, no war is 100 percent religious (or 100 percent anything) in motivation, but we can’t duck the fact that some conflicts involve more religion than others. So how can we decide when religion is the real cause of a conflict and not just a convenient cover story?
Well, for starters, if the only difference between the two sides is religion, then it is a safe bet that the conflict is religious. Serbs, Croats, and Bosniacs are basically the same people except for religion. Ditto the Dutch and the Flemings. In the French Wars of Religion, the partition of India, the Troubles in Northern Ireland, and the war in Lebanon, people who looked alike, spoke the same languages, and lived in the same communities were at each other’s throats only because they followed different religions.
Another consideration: How easily can you describe a conflict without mentioning religion? The American Civil War certainly had religious elements to it—John Brown’s fanaticism, Lincoln’s inaugural address, “The Battle Hymn of the Republic”—but you could easily write a detailed history of the war without mentioning any of these. Contrast that with, for example, the Crusades. Could you even get one paragraph into it without mentioning the pope, the Holy Land, or Jerusalem? You can argue that the Crusades were about something other than religion, but try writing two pages without bringing it up.
Finally, if the parties declare religious motives, we should at least consider the possibility that they are telling the truth. Religion is so central to a person’s worldview that most big decisions have some sort of religious consideration. Even if the warmonger-in-chief is using religion only as a convenient and cynical excuse to stir up the masses, the main reason he does that is because it works. You never see warmongers rallying armies to destroy an enemy that spells or shaves differently, because those are stupid reasons to fight a war. A different religion by contrast is usually accepted as a perfectly fine reason to kill someone. If it weren’t, why would people rally behind it?
Still, not every conflict between different religions is a religious conflict, especially when there are multiple differences between the conflicting groups. In the European conquest of the Americas, the desire to convert the natives fell far behind the desire to rob them. The Pacific war between the Japanese and the Americans is easily explained as a geopolitical power struggle. When the Turks pushed into Europe, religion played a role in motivating both attackers and defenders, but it was secondary to the simple empire-building that was occurring along all the borders of the empire.
For this list, let’s count only conflicts and oppressions in which religion is widely considered the primary reason for the conflict, along with human sacrifices and ritual killings.
The Thirty Deadliest Religious Killings
Taiping Rebellion (1850–64)
Twenty million died in a messianic uprising of Chinese Christians.
Thirty Years War (1618–48)
Seven and a half million died as Catholics and Protestants fought for control of Germany.
Holocaust (ca.1938–45; see “Second World War”)
Nazi Germany killed 5.5 million Jews all across Europe. Even though the Nazis claimed to be killing Jews for racial reasons, the only substantive difference between the victims of the Holocaust and those left untouched was their ancestral religion. It was the climax of several centuries of European anti-Semitism.
Mahdi Revolt (1881–98)
Five and a half million Sudanese died during this fundamentalist Muslim uprising.
Gladiatorial Games (264 BCE–435 CE)
Perhaps 3.5 million gladiators were killed to honor the Roman ancestors.
French Wars of Religion (1562–98)
Three million people died in the wars between the Catholics and Protestants of France.
Crusades (1095–1291)
For two hundred years, European Christians tried to wrest control of the Holy Land from the Muslims. Perhaps 3 million people died in these wars.
Fang La Rebellion (1120–22)
Two million died in a peasant revolt in China that started with friction between a Taoist emperor and a Manichaean minority.
Aztec Human Sacrifice (1440–1524)
The Aztecs sacrificed some 1.2 million people.
Albigensian Crusade (1208–49)
Around 1 million people in the south of France were killed in this war to exterminate the Cathar heresy.
Panthay Rebellion (1855–73)
A rebellion of Muslims in southeast China killed a million.
Hui Rebellion (1862–78)
Another rebellion of Muslims in northwest China killed 640,000.
Partition of India (1947)
Mob violence killed 500,000 Hindus and Muslims.
Cromwell’s Invasion of Ireland (1649–52)
Cromwell killed 300,000 to 500,000 Irish in his invasion.
Roman-Jewish Wars (66–74 and 130–136 CE)
A series of messianic revolts against Roman authority led to maybe 350,000 deaths.
The Bible
There are two sides to the debate about the atrocities described in the Bible: (1) God is merciful and everything described in the Bible is absolutely, inerrantly true, but the number of people slaughtered by the Israelites was wildly exaggerated, and those people deserved it anyway. (2) The Bible was written by mere mortals who made plenty of mistakes so you can’t believe everything you read there, but look at all of the people killed by so-called holy men in so-called holy wars in the so-called Holy Land.
Consider, for example, the city of Ai. The Bible states quite clearly that Joshua killed all 12,000 people in the city at the orders of God. If you are a fundamentalist, you have a lot of explaining to do, but if you are a heathen, you can simply point out that Ai means “ruin,” and archaeologists have determined that the town was destroyed long before the Israelites arrived in Palestine, so the Bible is wrong. This means neither side in the debate can comfortably use the Bible to support their interpretation of history.
Be that as it may, if we total the nasty bits of scripture, we’ll find 1,167,000 mass killings by humans specifically enumerated in the Bible. Perhaps a quarter of these (ca. 300,000) are historically plausible and religiously motivated.
Japan (1587–1660)
During the Shimabara Rebellion of 1637–38, the Christian rebel force of 20,000 fighting men and 17,000 women and children was wiped out, leaving only 105 survivors. Overall, the Catholic Church counts 3,125 named and 200,000 to 300,000 unnamed martyrs in Japan from this period.
Bosnia (1992–95)
When the predominantly Muslim republic of Bosnia-Herzegovina broke away from Yugoslavia, local Christian Serbs and the government in Belgrade tried to stop them. Two hundred thousand people died in the ensuing civil war.
Sati (outlawed in 1829)
The sacrifice of a widow on the funeral pyre of her husband was common practice in India, particularly in Bengal, where authorities recorded 8,000 satis between 1815 and 1828. Perhaps 60,000 or so widows were burned alive all across India during the preceding century, and a couple of hundred thousand since the Middle Ages.
English Civil War (1642–46)
In the struggle between the Puritans of Parliament and the High-Church supporters of the King, 190,000 Englishmen died, including, at the end, the king himself.
Lebanon (1975–90)
The country of Lebanon was originally carved out of French Syria to give local Christians a country where they could be a (slim) majority. By 1975, the national majority had shifted to the Muslims, so a civil war erupted over power sharing. One hundred fifty thousand people were killed.
Algeria (1992–2002)
Up to 150,000 died in a civil war that began when the military junta refused to hand over the government to Muslim fundamentalist parties that had won the recent elections.
Vietnam (1820–85)
A total of some 130,000 Catholic missionaries and converts were killed under persecution by several generations of Vietnamese rulers.
Russia (1919)
As many as 115,000 Jews were killed in pogroms by anti-Bolshevik soldiers in Ukraine during the Russian Civil War.
Byzantine Empire (ca. 845–55)
The Byzantine empress Theodora (not Justinian’s wife, this Theodora was the widow of Emperor Theophilus, the regent for Michael III, and a saint) hunted down and killed 100,000 Paulicians, followers of a Gnostic heresy.
Dutch Revolt (1566–1609)
The Protestants of the northern Netherlands rebelled against their Spanish rulers. The Spanish duke of Alva boasted of executing 18,600 rebels after he was sent to put down the uprising. In all, 100,000 people died in the revolt, including 8,000 in the sack of Antwerp. The Protestant lands became the independent Dutch Republic, while the Catholic south stayed loyal to Spain and eventually became Belgium.
Ukraine (1648–54)
During a rebellion against Poland, Cossacks under Bogdan Chmielnicki massacred as many as 100,000 Jews and wiped out three hundred Jewish communities.
Eastern Roman Empire (514–18)
When Emperor Anastasius appointed Monophysite bishops (who believed that the divine and human aspects of Christ were separate) rather than Chalcedonian bishops (who believed that the divine and human aspects of Christ were unified), General Vitalian (a Chalcedonian) rose in rebellion against him. Sixty-five thousand people died in what Edward Gibbon called the first religious war.
Witch Hunts (1400–1800)
Sixty thousand accused witches were burned or otherwise executed all across Europe.
Thuggee (until the nineteenth century)
This mystical cult of thieves and stranglers may have sacrificed around 50,000 travelers to the goddess Kali.
In God We Trust
If we categorize the entries in this list according to which religions came into conflict, we get this simplified breakdown:
Christian vs. Christian: 9
Muslim vs. Christian: 3
Christian vs. Jewish: 3
Eastern vs. Christian: 3
Jewish vs. pagan: 2
Muslim vs. Chinese: 2
Muslim vs. Muslim: 2
Human sacrifice in India: 2
Human sacrifice in Mexico: 1
Ritual killing in Rome: 1
Muslim vs. Hindu: 1
Manichaean vs. Taoist: 1
We can probably go even farther and group them into four larger categories: indigenous human sacrifice, monotheistic religions fighting each other , heathens fighting monotheistic religions , and heathens stirring up trouble all by themselves. In early history, the majority of religious killings involved sacrificing people to bribe and placate the dangerous forces of the universe. Then, Judaism and its offshoots, Christianity and Islam, devised a worldview where a single all-powerful god required a strict, uncompromising belief rather than tangible offerings. After that, religious killings tended to arise from the friction of incompatible beliefs.
Notice that followers of Eastern religions haven’t often killed each other over who has the better god. Nor have pagans, shamanists, and animists. These relatively flexible religions usually keep calm until they bump up against rigid monotheists.
Although most of us favor religious tolerance, that is a losing strategy in the end. Monotheism’s intolerance of rival beliefs is one of the main reasons why it has succeeded in replacing the more relaxed indigenous religions of Europe, Africa, America, and the Middle East.
Written by Matthew White in "The Great Big Book of Horrible Things", W.W. Norton, New York/London. Digitized, adapted and illustrated to be posted by Leopoldo Costa.