The First Crusade: Causes and Effects

A Plea for Help

In 1095, the Byzantine Empire was in trouble. A recent invasion of Turks had seized control of the Byzantine holdings in Asia Minor and was beginning to threaten the city of Constantinople itself. The Byzantine emperor, Alexius Comnenus, wanted to reconquer this lost territory, so he wrote a letter to the pope asking for help.

Comnenus probably just wanted the pope to send him some Western mercenaries to help with the fighting. It is unlikely he ever imagined the repercussions of his letter. The emperor's plea for help was received by Pope Urban II. Unfortunately for Comnenus, Urban had a very different response in mind.

Pope Urban II

Rather than a band of mercenaries fighting for cash, Urban would send the Byzantine emperor a horde of Crusaders fighting the infidel for the glory of God. However, Urban's plan, probably inspired by the Spanish Reconquista, was more about increasing the authority of the Church and pope than it was about helping the Byzantine emperor.

Indeed, one major incentive for the First Crusade was the Pope's desire to bring the Greek Orthodox Christians of the East under the control of the Roman Catholic Church in the West. By helping Byzantium reclaim its territory, Urban hoped to make the Byzantines dependent upon the West and bring its people back into the fold of Western Christendom.

Yet Urban was not just interested in expanding his power in the East. He also wanted to reinforce his power back at home in the West. The recent Investiture Conflict & Gregorian Reforms had shaken up Western Europe and challenged the pope's authority. The papacy was being challenged by the lay nobility, especially the Holy Roman emperor, Henry IV, whose growing military power had driven the Pope from Italy to France. The First Crusade can be seen as the Pope trying to reassert his power and authority in Europe.

All of these reasons seem very practical and only marginally related to religion. Though it is tempting to view medieval history through this cynical lens, it is also important to remember that this was a very religious time. The Pope may have had a number of religious reasons to call this crusade. The most likely religious reason for the First Crusade was Urban's desire to establish peace in Western Europe.

This whole concept may seem odd, since the Crusades were, essentially, a call to arms. Yet Urban had made his peaceful intentions clear earlier in the year. Urban had already given papal approval to several peace-minded policies, including the Peace of God, which protected non-combatants, and the Truce of God, which forbade warfare on certain holy days. Yet Urban knew that warfare was an integral part of medieval society.

As we've noted in other lessons, the entire feudal system was set up to build feudal armies. Yet as Europe became fully settled with territorial borders established and the last heathen barbarians driven from Europe, the armies of Christian lords had no one to fight but one another. Urban did not mind Christians killing Muslims; he just didn't want Christians killing Christians. Urban hoped to redirect the warlike tendency of Europe in a more productive vein and assert his power unto both Eastern and Western Europe all in one fell swoop.

The Pitch: Clermont

Urban delivered his sales pitch for the First Crusade at a council of clergy in the French town of Clermont. There, Urban gave a speech calling on the people of France to rescue Jerusalem from the hands of the infidel. The speech exaggerated the threat of Islam in apocalyptic terms. Listening to Urban, one would think that all of Christendom faced the imminent threat of annihilation from Muslims. To rile up the crowd, Urban accused Muslims of committing horrible atrocities against Christians.

It is worth noting that these claims were almost all false. Islam displayed a religious tolerance that was remarkable for its time. In the years to come, the real religiously motivated atrocities would be committed by Christians against Muslims, not the other way around.

Though Urban played upon the French reputation for piety and bravery, he also offered incentives for those with more selfish motivations. He promised papal protection of Crusaders' property and family. He hinted at the opportunity to carve out new kingdoms in the Holy Land.

Most importantly, he offered indulgences for those who could take the Crusader's oath. Essentially, this meant that anyone who went on Crusade would have all their sins forgiven and go directly to Heaven upon their death. Though these get-out-of-Hell free cards would cause the Church a great deal of trouble in the centuries to come, at the time, it proved an incredibly powerful motivation for lords and peasants alike.

The People's Crusade

Urban's speech at Clermont was copied and recited across Europe. It is unlikely that even the Pope anticipated the scope of Europe's response. One of the most surprising effects was the People's Crusade.

Extemporizing on Urban's speech, the local priests of Europe whipped up lots of poor city folk into a religious frenzy. Estimates on the People's Crusade vary, but an army of anywhere from 40-100 thousand unskilled peasants marched east from Northern Europe to cleanse the world of nonbelievers.

Unfortunately, this included their Jewish neighbors. As this mob worked its way east, it engaged in vicious pogroms, wiping out entire Jewish populations wherever it passed. Like a swarm of malignant locust, they scoured the countryside, causing havoc and terror, which seems terribly at odds with their own religious convictions.

When this horde arrived at Constantinople, the terrified Byzantine emperor quickly shipped them across the Hellespont, where they were slaughtered to the man by the Turks.

Religious Motivations

Such suicidal religious fervor on the part of peasants highlights the desperate state of city peasants in the 12th century. It also draws our attention to the power of religious piety in this age.

Scholars have offered a variety of explanations for this religious fervor. Some point to the apocalyptic energy of the Millennials, who thought the world would end in the year 1000. In the disappointment that followed, this energy was redirected towards religious fervor.

Other scholars have suggested a far more secular cause. One of the most entertaining is the notion that the increased cultivation of rye and ignorance on how to store this grain resulted in an outbreak of ergotism. When rye rots, it creates a poison, which causes convulsive movements and even hallucinations. The fact that these ergot-driven spells came on so suddenly must have seemed demonic to the people of Europe. The fact that this affliction could be relieved simply by stopping the consumption of rotten rye from dank basements may well have given rise to a new wave of religious conviction.

This explanation also helps us to understand the popularity of pilgrimages in this age. As Europe began to stabilize, pilgrimages to holy sites became ever more popular. Though many factors contributed to the popularity of these pilgrimages, the rise of ergotism might have played its own part. A man struck with ergot poisoning might well go on a pilgrimage to attain healing. People who went on pilgrimages stopped eating rotten rye from dank cellars and thus returned healthy. In many respects, the Crusades can be seen as an armed pilgrimage to the Holy Land.

Secular Motivations

While the peasants who participated in the People's Crusade were clearly inspired by religious fervor and perhaps by the desperation of their plight in Europe's overcrowded cities, the motivations of the French aristocrats who went on the first legitimate Crusade are harder to pin down.

There clearly was at least some degree of religious motivation, since there was no guarantee that a Crusader would see any return on his investment besides a shallow grave in Palestine. Yet some segments of medieval society clearly saw a chance to improve their status and power by crusading.