The First Crusade Essay

The Causes of the First Crusade: a Historical Analysis


Forty years before the First Crusade, in 1054, the Christian Church experienced a major schism. Combined with the major rise in Islamic influence this schism weakened power of the Church and, in particular, the Papacy. In an attempt to aid the Byzantine Christians the Pope may have been trying, in a way, to reunite the Church. The more cynical views posit that the Pope was merely trying to increase the range of his own influence and power.

In the eleventh century, religious leaders like the Pope were much more powerful than they are today. Now we take for granted the separation of Church and State. Religious leaders have influence but real power is held by politicians. In the Middle Ages there was no such separation. For all intents and purposes the Church was the State. Today, the Church no longer holds political authority, at least in the Western world. Religious war still exists however. What is it about religion that can lead to war? This is an important question in the 21st century. Examining the causes of past religious conflicts can help to do the same with today’s conflicts. The better prevention strategies can be formulated from the past lessons. The First Crusade was a religious war, but its causes were much more diverse and complex.

Chronology of War

Launching a crusade required a large amount of planning efforts. To unite willing fighters from all over the Europe would be a difficult intention. This particular type of war would require something more. “In addition to fighting men and adequate supply lines, crusading required spiritual authorization by the Church, which in Western Europe meant the papacy” (Magadalino, 1996, n.p.). This led to unprecedented actions by the Catholic Church and a fundamental change in the philosophy of war.

In 1095 Pope Urban II began the First Crusade. He was responding to a call for help from Byzantine Emperor Alexius I. Byzantium was under attack by Turkish forces. The Turkish troops had advanced to Nicaea, close enough to put in danger the Christian capital of Constantinople. Alexius sent emissaries to the Council of Piacenza to ask for help. The Pope agreed to provide assistance. The initial intent of the Pope’s action was not to battle a “religious war”. Instead, the goal was only to repel the attacks of the Turkish forces to maintain the Christian Empire as it stood. As the conflict escalated, the war acquired a more religious nature (Partner, 1998).

Frenzied Christian troops wanted to do more than just defend Byzantium. Consequently, the second goal for the Crusade was created. Christian forces wanted to recapture the sacred city of Jerusalem, now held by Islamic forces. The war then drew participants from many nations at the same time as both the goals and the geographic range of the conflict escalated. In 1099, Christian forces successfully recaptured Jerusalem which led to the formation of several other Christian controlled states.

In 1097, Crusader forces along with a contingent from Alexius’s army set their sights on Nicaea. A former Christian city, it was now the capital of the Seljuk Sultanate of Rum. After the long siege, Christian forces recaptured the city. Under prior agreement with Alexius, crusader troops were not allowed to raid the city or enter it. Byzantine troops only took control of the city. After regaining Nicaea, a combined Christian force of Normans, French and some Byzantine troops continued their march through Anatolia. Initial resistance from the Turkish lines was broken through and the army then began to move through quickly. This course was quite efficient however. Internal disputes about leadership still plagued the undisciplined army. The army was never supplied in a professional manner. The troops gained some support from Christians in the newly conquered territories. Even more, the supplies often were acquired by pillaging the countryside. Those who refused to cooperate were killed, often in a brutal manner (Runciman, 1980, p. 31).

In late 1097, the crusaders began the siege on the ancient city of Antioch. This city was located in a strategically and religiously important location – on a mid way between the holy city of Jerusalem and the Byzantine capital of Constantinople. Defense of the city was fierce; after the eight-month siege the city fell. Crusaders entered the city and massacred most of its residents. Ironically, it was only few days until another Islamic army arrived and began a siege of the city themselves (Runciman, 1980).

Forces led by Bohemond of Taranto eventually outlasted the Muslim forces. What should have been a uniting moment proved to be the opposite. Bohemond claimed that Byzantine Emperor Alexius had not participated fully in defending Antioch. Bohemond, therefore, claimed the city for himself. All forward progress in the Crusade was halted for a year as the opposing claims were hashed out. In 1098 a plague slowed progress even more. Horses, food and able troops were in short supply. It would take until 1099 for the forces to regroup and resume their push toward Jerusalem (McCullough, 1998).

Upon reaching Jerusalem the Crusaders encountered an unexpected force. A year before, the Seljuks, whom the Crusaders had defeated in Nicaea, were expelled from Jerusalem by Egyptian forces. Again the Christians began a siege of the city. This time it was remarkably successful. It took only a week for the Christian forces to breach the city walls. Unfortunately, a lot of the city inhabitants were killed. Interesting, Jerusalem had a substantial number of Christian residents prior to the time of the First Crusade. There are reports that, in addition to the slaughter of Muslims and Jews, the Crusaders also killed local Christians (Fremantle, 1965, pp. 37-41).

At the same time, Alexius, the Byzantine Emperor was entirely focused on the defense of the Western Empire. The troops that came to defense him had other concerns. For them, this was a Holy War that had to end in Jerusalem, and not before. Neither the Pope nor Emperor Alexius fully controlled the actions of the Christian troops. As a result the conflict spread exponentially (McCullough, 1998).

Crusader states, including those in Jerusalem, Tripoli, Edessa and Antioch were established by the end of the First Crusade. These states, for a certain period, would provide a buffer against Islamic invasion into Europe. Unity among the varied Crusader troops continued to be a problem at the same time as they tried to defend newly conquered territories. In the 12th century Islamic forces under Saladin would once again capture Jerusalem. The crusade that began in 1095 was far from being the end of religious war. Instead, it was the beginning of religion-based conflicts that raged out, in one form or another, even up to the present day.

The Underlying Causes of the Crusade

By the late 11th century the Christian Empire that once spanned Europe and Asia Minor was in disarray. In 1071, the Turkish army defeated Emperor Romanus IV leading to a rapid devastation of the easternmost portions of the Empire. The military forces of the east were largely destroyed. This situation created an opportunity for attack along the huge part of Christian territory. The trigger for the Crusade was the request for a help from Rome by the Byzantine Empire. However, the Western Empire itself was already endangered by the devastation in the east. As the more militant wave swept throughout Europe the Pope saw an opportunity to defend Byzantium while simultaneously increase his own power (Nelson, 2009).

Pope Urban II was not the first Pope to call for intervention in the east, but he was the first to launch a substantial campaign. Twenty years earlier Gregory VII had hoped to launch a similar mission but conditions in Europe at the time were not favorable for recruitment of a huge force. In 1095 Urban II knew that he had to create an 11th century version of a public relations campaign. The Pope found a fertile ground for recruits in his home country of France. At the Council of Clermont he gave an assessment of cruel Islamic misdeeds and harassment of Christian settlements. Many influential nobles attended the council and were horrified by the Pope’s allegations (Fremantle, 1965, pp. 51-3).

Meanwhile a trend was occurring in Europe. People were becoming more connected with their religion in a personal sense. They were moved to participate more actively in their spiritual life. One outcome of this was a substantial increase in the number of religious pilgrims traveling to the Holy Land of Jerusalem. The Pope capitalized on this trend to marshal support for the First Crusade. “Combined with the pilgrimage ardor, the propaganda roused Western Christendom to fever pitch” (Fremantle, 1965, p. 55). The Pope’s speech at Clermont kicked off this campaign. That speech has become an essential element in explanation of why the Christians went to war.

Existing versions of Pope Urban’s speech differ from one another, but there are several elements they have in common. Muslim crimes against Christians in the Eastern Empire were described in vivid details. The need to help the Eastern Christians was outlined. Even more importantly, the template for a new type of war was presented. The Pope described a military pilgrimage in which those who died in battle would be forgiven of sins and ascended straightly to heaven. It still remains in question as to whether the Pope mentioned the re-conquest of Jerusalem in his initial recruitment efforts (McCullough, 1998, pp. 311-5).

Every good campaign has a slogan. The Pope provided one at Clermont, to devastating effect. “A simple slogan – “Deus Vult,” God wills it – inspired thousands to march into the Middle East and begin what turned out to be centuries of bloodshed” (McCullough, 1998, p. 321). The Pope succeeded in his recruiting efforts for the First Crusade. Unfortunately, it would turn out to be the first crusade of many to come. His impassioned appeals would draw more than just professional soldiers.

For many, the Crusade became a family affair – entire families ceded their land and other assets to the Catholic Church then went to battle together. Urban’s campaign had energized the common people. Europe in this era was already a violent place. Knights and nobles were conflicted about the sin inherent in this violence. Now there was an outlet for violence – that, according to the Pope, was sanctioned by God. These families were often headed by knights who was all ready to go to the war.

European knights in the eleventh century were adventure-seeking souls. Devoted Christians, they dreamed of the opportunity to create a new Christian Empire. The new goal of recapturing Jerusalem drew knights in large numbers, especially from France. They the rode into battle with romanticized notions of honor, valor and combat. The Pope would not have to wonder a long about the success of his propaganda campaign (Fremantle, 1965).

Recruitment of the Normans was critical to any projections for success against the Turks. At that time it was believed that the Normans were the only force capable of victory against the powerful Islamic Empire. For years prior to the Crusade, Norman knights had traveled to the East and become familiar with the Islamic cultures there. They saw opportunities there, both to expand the Christian Empire and to increase their own personal fortunes. For the Latin Christians in Rome, an alliance with their French and German neighbors was somewhat unnatural. The Germans in particular were viewed as barbaric and lacking in intelligence. The strength of the Islamic Empire, however, forced a marriage of convenience. The plan for all forces was to unite at Constantinople (McCullough, 1998).

A group of knights and nobles was so inspired by the Pope’s charge that they set off for Jerusalem on their own. This small army was led by a priest named Peter the Hermit. His impassioned leadership stirred fervor among his people. But the Pope had planned to launch this campaign only several months later. Not surprisingly, the untrained force was not prepared for such a task. Eventually they arrived in Constantinople to participate in the conventional battle plan. They united with other European forces. The initial battle for these troops was just to gain food and supplies. They raided the surrounding areas before crossing into Asia Minor. The untrained, undisciplined Christian troops would not prove to be the opponents for the Turks. Most were killed by skilled Turkish archers. The remaining survivors struggled to survive. Against all odds, the first armed pilgrimage to the Holy Land was successful, and the Christians captured Jerusalem in 1100 (Nelson, 2009).


The Crusade itself took a number of forms depending on the individual motivations of its participants. In Germany, European Jews were increasingly subject to persecution. Some were killed; others were forced to convert to Christianity. Jews were also extorted by being forced to pay protection money. Persecution of the Jews was never part of the official Crusade as was presumed by the Pope. Some priests took steps to protect the Jews. Others preached that the Crusade should be fought just as much against the Jews as against the Muslims. Jews, in their view, were responsible for the death of Jesus Christ. Therefore, they were enemies as much, or even more that the Muslims (Partner, 1998).

The anti-Semitic character of the crusade in Germany had its roots in finance. The Jews had established several successful colonies in Germany. In the colonies, money lending houses were established. At the same time, the Crusaders needed money. As Runciman (1980) puts it: “It was expensive for a knight to equip himself for a crusade; if he had no land and no possessions to pledge, he must borrow money from the Jews” (p. 63). Antipathy toward the Jews grew steadily. Christian priests debated whether it was right to be financially beholden to the Jews in order to conduct a Christian crusade. Some rationalized that it was “more correct” to just take what they needed. After all, they saw the Crusade itself as a holy mission (Runciman, 1980).

This is one example in which Christian principles were compromised in the process of justifying a Holy War. Another was in the sheer brutality of the combating. At every stage the conflict was vicious. Each side looked upon the other as being barbarians. No quarter was given. Christian troops even resorted to cannibalism, carving and devouring the bodies of their Muslim foes. First hand reports are chilling. In the words of one Norman soldier upon entering the city of Jerusalem: “Our men followed, killing and slaying even to the temple of Solomon, where the slaughter was so great that our men waded in blood up to their ankles” (McCullough, 1998, p. 341).

What could have caused such brutality? Considering the nature of war at the time, the level of violence was not terribly surprising. What was surprising that these soldiers were essentially representatives of a Church of Peace. A major leap in philosophy had been made. The Church no longer viewed all war as sinful. War in the name of religion, as they saw it, was sanctioned by God (McCullough, 1998).

At the same time, the motives for any war are usually more complex than they appear at first sight. Not all the motives are rational or even achievable. Fremantle (1965) writes that “There were mixed motives behind the Crusades. Even the declared intention for which they were launched…was somewhat flawed” (p. 53). The Church wanted to exert ultimate control over the Crusade effort. Its motives, however, were tangled with other regional, cultural and individual motives. Nobles were looking for a place to send their energetic sons. The Church was looking for new lands to place problem-causing clergy. Passionate faith and reverence for the Holy Land urged many individuals to leave their lives in Europe for a mission that had a high risk of failure. Regardless of their reasons for entering all faced a difficult and deadly challenge (Fremantle, 1965).

The First Crusade ultimately was an attempt to respond to the many Islamic conquests that had occurred in prior centuries. What began as a European battle escalated into a larger multi-regional war. The Crusade also had commercial repercussions in addition to being a ordinary religious war. The fall of the Western Roman Empire greatly damaged the prospects for international trade. After the First Crusade these opportunities began to re-emerge and became more evident.

Muslim conquests had occurred centuries prior to the First Crusade, so most historians believe that the Crusade was not started as a direct response to these conquests. Muslims and Christians, in fact, had been living in close proximity for several centuries. Christians were living in Palestine with a relatively low level of persecution. Pilgrims to the Holy Land were taxed but usually not prevented from reaching their destination. There were isolated events that agitated the fragile relationship between Muslims, Jews and Christians closer to the time of the crusade however. The destruction of the Church of the Holy Sepulchre by Muslim forces in 1009 prompted calls for a military invasion. The invasion did not occur and the church was rebuilt. Still, pilgrims on their way to the new church were subject to harassment from Muslims (Runciman, 1980).

Church reform also played a role in the First Crusade. A new wave of religious thought was taking hold in Northern Europe and in Byzantium. In many cases, this thought was spawning a personal and more independent form of Christianity. The control the Catholic Church and Pope exerted over Christianity was increasingly called into question. The result was the even more fragmented Christian Empire.

The spirit of religious reform that had led to the Investiture Controversy had been accompanied by an increase in popular spirituality. People were no longer to accept their religion passively; many wanted to participate actively and to do something positive in honor of their god. (Nelson, 2009, n.p.)

Meanwhile, the Catholic Church was developing theories of Just War and Holy War that justified both the defense and the advance of the Christian Empire. In part, the First Crusade was an attempt by the Pope to reassert control over the Christian religion. The early Christian Church had not been an advocate of a just war theory. Its influence set the ground rules for society at the time. The soldier was not a figure to be idolized. For the fighting soldiers, to the necessary extent that was simply a job. Christ and John the Baptist were martyrs; soldiers were not. “Death in battle was not considered glorious; and death in battle against the infidel was not martyrdom; the martyr died armed only with his faith” (Runciman, 1980, p. 33).

In the long run, the schism in the Christian Church and the rise of Islam probably had something to do with a change in perspective about war. When the Pope went public with this change, he tapped into a variety of societal undercurrents including the culture of knighthood and the anti-Semitism of Northern Europe. In doing so the Pope caused effects he had not intended and could not control. A sense of idealism may have been the primary motivational force for the undertaking of the First Crusade.

As with any war, however, there were a number of side issues that also helped to force the war movement forward. Overpopulation in certain parts of Europe led to a drive to colonize new areas. A series of poor harvests in Europe was also making it difficult to feed the expanding population. Fear of the influence of Islam on religious, cultural and commercial aspects of European society led many who were not necessarily the most devout of Christians to the fight (Partner, 1998).

Many Crusaders entered the conflict with a naive idealism about what the war really was. Conflict was brutal and inglorious. Even more deadly were the diseases, starvation and lack of supplies that plagued the troops. Assessing the question “why did they go?” can help us learn from history in a time where religiously-based warfare is still all too common. The Crusaders fought against long odds. They persevered despite many early setbacks. The conflict raged in several different directions simultaneously. Individual knights and rulers tried to use the conflict for self-serving purposes.

The primary conflict of the First Crusade was between the Islamic Empire and the Western Christian Church. The Byzantine Empire provided the initial battleground but it also played a significant role in triggering the conflict itself. According to Magadalino (1996):

The important point is that the empire was not a helpless and passive spectator to the confrontation between Latin Christendom and Islam; the confrontation occurred because of, not in spite of, Byzantium. (n.p.)

The Byzantine Empire wanted to force away the invasion of Islam. At the same time, it also wanted to resist the influence of its allies the Roman Church. The Crusade was a military war. It also was a commercial, cultural, racial and religious power struggle.


The First Crusade was successful in many aspects. Several Crusader states were formed. These state helped to protect the Byzantine Empire from Islamic forces. A period of relative prosperity followed. International trade routes had been expanded. “For the first time since the fall of the Roman empire, western Europe was not isolated, but a part of a greater world” (Nelson, 2009, n.p.). In Eastern Europe, the First Crusade triggered a renaissance in literature and art. The exploits of the Crusaders reached legendary status. Many well-known Crusaders became the subject of near-worship. Interest in the holy land and the roots of Christianity was stoked even further.

From the perspective of the Pope, the First Crusade was a mixed consent. It was achieved many of its military goals. The Byzantine Empire had been defended and Jerusalem had been reclaimed. The crusade had not repaired the schism that broke the church apart in 1054 though. Reformation thought continued in earnest, particularly in Northern Europe. The lack of cooperation between the many factions of the Crusader army eventually led to their expulsion from many of the territories they had fought so hard to conquer.


Fremantle, Anne. (1965). Age of Faith. New York: Time-Life Books.

Magadalino, Paul. (1996). The Byzantine Background to the First Crusade. Toronto: Canadian Institute of Balkan Studies.

McCullough, David Willis (ed.). (1998). Chronicles of the Barbarians: first hand accounts of pillage and conquest from the ancient world to the fall of Constantinople. New York: Random House.

Nelson, Lynn Harry. (2009). Lectures in Medieval History: The First Crusade. University of Kansas. Accessed 4/10/2009 from: .

Partner, Peter. (1998). God of Battles: holy wars of Christianity and Islam. Princeton, NJ: Princeton University Press.

Runciman, Steven. (1980). The First Crusade. New York: Cambridge University Press.