The Crusades that took place entirely within Europe aren’t really part of the narrative of the Muslim Empire, and its contacts and conflicts with Europe, that I’m primarily telling. However, it’s worth seeing how the idea of “crusade” developed during that time, and I think it also helps put the remaining Holy Land crusades in context. We have to start with the church’s view that loss of Jerusalem was punishment for group sin; one of the sins was tolerating paganism or heresy, thus weakening Christendom. To stop losing, they had to stop tolerating heresy.
Europe’s largest counter-cultural religion at this time was the Cathar religion. It seems to have developed during the Dark Ages in Armenia, diffusing through parts of the Byzantine Empire, especially Bulgaria. In the century before the Crusades, the Byzantines used a group of these believers, called Bogomils (Friends of God), as a frontier population stabilizer in Thrace (north of Greece). Travelers through Thrace brought the new theology to Northern Italy and Southern France, where its adherents became known as Cathars, the Pure Ones.
Catharism had little in common with orthodox Christianity. It posited a dual set of gods, good and evil, one of spirit, the other of the material world. Food and sex were bad, while everything of the spirit was good. Priestly hierarchy and civil authority were both bad; Cathar believers would not take vows, so they could not serve in the army or courts. For the most part, Cathars lived side by side with Roman Catholics, as different sects do in modern times. In the region around Toulouse, there had been Cathar believers for several generations by the time the Pope decided to put a stop to it.
Previous church councils had labeled it as wrong, but nothing had been done. Now, Pope Innocent III decided to use the tool of Crusade. He proclaimed forgiveness of sins, and a reward of land, to any French knight taking the Cross against the Cathars.
The knight who stepped forward to lead was an Anglo-Norman who had actually left the Fourth Crusade when he saw it was going to attack fellow Christians. Simon de Montfort had traveled to Hungary instead, and then to Acre. Now he was back on his lands in France, looking for a new Crusade. The French knights of Southern France were very reluctant to actually kill the Cathar believers among them, but Simon de Montfort apparently had no sentimentality about them. It seems likely he was also ambitious to increase the legacy he left to his heirs, and there were some very good estates owned by Cathars.
So in 1209, Montfort met with 10,000 knights and soldiers in Lyon. They besieged the town of Beziers, knowing it had a mixed population of Cathars and Catholics. They told the populace that the Catholics should come out, and the Cathars should surrender. When the city gates were forced open, the Crusaders killed every resident of Beziers and set it on fire. The papal legate who accompanied the troops was untroubled by the deaths of so many Catholic believers too, including priests killed at their churches. It was worth their deaths to defeat Cathars.
The walled city of Carcassonne prepared to defend itself, but after the besiegers cut the water supply, the town surrendered. During the surrender negotiations, their Viscount was imprisoned and didn’t come out alive. The rest of the people were expelled. Most other towns surrendered after this.
The town of Minerve didn’t surrender, and after its fall, while most residents were expelled alive, 140 Cathar leaders were burned at the stake. As happens with war, the savagery increased with time. When 6000 Crusader reinforcements were ambushed by the men of Toulouse, all but one were killed. The next time Simon de Montfort took a castle, he hanged the lord and all his knights and burned several hundred Cathars.
In the midst of all this, priests came behind the army and conducted an Inquisition. It was an investigation, and it was carefully recorded, word for word. The documents have survived and historians find them a rich source of information on daily life and culture. For several years, teams of priests questioned locals about Cathar believers or witchcraft, and they often asked details information about the neighbors: who was married to whom, who did what work, who thought what about their neighbors’ beliefs.
From the Inquisition documents, it appears that the priests had no zeal for physically punishing the people they were questioning and they often just assigned them acts of penance. From our modern point of view, it was still suppressing a faith that some people held as a matter of conscience. We can’t give our approval. But it was much gentler than the later Reformation-era Inquisitions.
But the military destruction of the region continued for several years, too. In 1211, the Count of Toulouse called on King Peter II of Aragon to help them. Peter was a good Roman Catholic, but his sister had married the Count of Toulouse; they were near neighbors in a time when Southern French and Northern Spanish were essentially the same language. So the grand finale battle of the Cathar Crusade pitted Simon de Montfort against Toulouse and the Aragonese knights. In the Battle of Muret, King Peter was killed. Simon de Montfort was victorious again! The Count of Toulouse fled to England for sanctuary, and the Crusaders occupied most of the Toulouse region. In 1215, the last fortress fell, and Simon de Montfort became, in effect, the Count of Toulouse.
Still the fighting did not stop. It was an ancient, proud, independent region. The Raymonds, father and son, fought back while the King of France started joining on the Crusader side. That’s the tip off that if political conquest hadn’t been the original goal, it surely had become it. The men of Languedoc sometimes won back their land, but the tide was against them. It was now a war of France vs. Toulouse, with religion as a formal excuse. It finally came to an end in 1229 when Queen Blanche offered a truce to Raymond (by now these were both 2nd generation inheritors of the Crusade) in which his daughter married Prince Alphonse of France, and from that time, Toulouse would be a Crown property. Raymond had no option but to accept.
The culture and land of Southern France had been laid waste. Wars tend to get more bitter as they go, and in this one, the “Crusader” forces had begun wantonly burning vineyards and fields all around Toulouse, smashing what they could find. It took years for agriculture to recover, and the arts culture of Provence and Toulouse never recovered. Troubadours who fled the genocide went northward, gladly received in less cultured cities and courts. That’s how the southern troubadour music reached Paris and London, then even cities along the Rhine. And the Cathar religion came to an end, as the Inquisition went on for years in the desecrated region. After that, they were just a region of France.