The combination of military force and Christianity affected both Christianity and the shape of the world at large after the Emperor Constantine ordered his troops to mark their shields with the Chi Rho symbol of Christianity at the battle of Milvian Bridge. With this example conflicting with the apparent renunciation of violence found in the New Testament, Augustine of Hippo published his doctrine of Just War as guidelines for Christians called to render military service or defend their homes. The belief that Christians could rightly take up arms had a lasting impact on the development of European civilization and its interactions with the wider world. Relying on Augustine’s doctrine, Christians fought to defend themselves from outsiders, launched the Crusades to the Holy Land, and engaged in wars among themselves.
When later theologians further refined Augustine’s understanding of the circumstances under which Christians might use force, they armed themselves against each other in conflicts over political and religious dominion. President George W. Bush invoked an ideology derived from Christian ideology of Just War in launching the invasion of Iraq, and worsened American relations with the people of the Middle East by calling for a “Crusade” against Islamist terrorism. Since the combination of Christianity and arms continues to play a significant, even dominant role in the world, it is necessary to revisit the development of Western European Christian theology regarding the use of force through the Pope Urban II’s call in 1095 for the First Crusade.
The effort to lay ground rules for the just prosecution is an ancient one. In The Republic Plato illustrates the early Greek view of proper warfare. He argues that soldiers should kill only combatants, leaving women, children, and the elderly unscathed. He also contends that armies should refrain from destroying homes, as this would create undo hardship for those remaining after the war is over. He limits these protections only to Greeks. Non-Greeks might face a harsher form of warfare when they fought Greeks. Building from Plato’s work, Aristotle extended the doctrine of proper warfare to include acceptable reasons for engaging in war. He believed defense, revenge, helping allies, seeking new resources for the polis, or to maintain power over subject peoples were all valid justifications for war.
Writing in 44 BCE, Cicero contended that war was acceptable only to maintain the security and honor of the Roman state. His rationale was that by doing so, the legions ensured peace for Roman citizens. However, as Roman, Cicero extended the definitions of maintaining security and honor to include wars fought solely for honor. The conduct of war should conform to the goals of the war, and the conduct of the enemy. Roman armies should protect enemies that surrendered, even if they resisted a siege. Wars fought for glory, or financial gain, should proceed without malice or brutality, while those fought for survival, or against barbarians should have only survival as the goal. In Cicero’s analysis Carthaginians merited their fate due to their duplicity after the conclusion of the first two Punic Wars. His three criteria for a Just War provide the basis of Christian and European conceptions of Just War: there must be a just cause, there must be a formal declaration of war by the ruler, and war must be conducted justly.
In the three centuries between Cicero and Augustine, early Christians struggled with their proper role in civil life, particularly in political and military service. There were multiple reasons for confusion among Christians as to their proper relationship with the use of force. Christ’s instructions to turn the other cheek and the Sixth Commandment’s injunction not to kill conflict with both Old and New Testament images and instructions to use force. Jewish Mosaic Law, based on the Old Testament, allowed both execution for crimes, and killing in self-defense. The Torah also depicts Yahweh as a martial leader, directing Joshua to kill unbelievers. This image is leavened by Yahweh’s instruction to not destroy Canaan, and David’s inability to build the Temple due to his status as a warrior. Similarly, the Psalms provide repeated injunctions against war and cruel weaponry.
The New Testament also provides believers with a conundrum. While Jesus clearly tells Peter that those who live by the sword will die by the sword in the Garden at Gethsemane, and to turn the other cheek, Paul’s letters to the Ephesians provide many martial images, including wearing armor, and fighting the forces of darkness. The language Paul uses while proselytizing is rife with the language of war and conflict, or struggle against demons. Adolf Harnack argues that Paul’s imagery, as well as that of Christ, help create a mental outlook in early Christians based on confrontation with the world. The popularity of Apocryphal Gospels that portray Jesus as a powerful and vengeful figure exacerbates the confusion created by the contents of the New and Old Testaments. In 96 CE, the Roman Clement envisioned Christians not only as soldiers of God, but of being in a military hierarchy like that of the Roman legions which embodied their commitment and their discipline.
With the contradictions that seem inherent in the Bible, it is no surprise that Early Christians were themselves confused about whether they could serve in the military, or act in their own self-defense. In addition to the mixed messages they received from the New Testament, Hippolytus contended that Christians could not fight, even if they served in the legions. However, they could not desert due to the combination of making Christians look deceitful and Paul’s response in Romans 13 in which he contends that the state has the power to punish and that Christians must bow to its divinely instituted authority.
As may be expected, there is no definitive evidence of Christians serving in the legions until 173 CE. At this time, the debate over whether Christians could serve in the military was continuing. Origen argued that the wars of the Bible are not a call to arms for Christians, but allegory for wars against sins. He believed that Paul preached for only wars of the spirit using the language of wars of the flesh so that less philosophically minded people would understand his message. Only ascetics, or those that have abandoned civic life, are truly the warriors of God. In Origen’s interpretation, truly Christian ascetics fought spiritual battles against heretics. In response to the criticism of Christians for not serving in the army, Origen argued that if all Romans were like Christians, their barbarian opponents would convert to Christianity and restore peace.
Similarly, Tertullian and Cyprian argued against military service for Christians. Cyprian contended that all killing, without exception, was wrong because there was no separation between public and private morality. In effect, Cyprian claimed that any reading of Romans 13 that allowed Christians to kill was a distortion of Christ’s message of peace. Tertullian also argued against military service for Christians as both a violation of Christ’s dictum to turn the other cheek, and because the requirements of service posed a threat to Christians’ immortal souls. Both enlisted men and officers serving in the legions practiced idolatry as part of camp culture. Roman military practice also required officers to make sacrifices to pagan Gods as part of their leadership functions. Christians could not perform either task without breaking the two of the Ten Commandments, and thus should not serve.
Tertullian also echoed Origen’s interpretation of Christians as spiritual soldiers in the contest against evil. Tertullian, the son of a legionnaire, saw baptism as a military oath. Because of this, he argued that all Christians were soldiers, and that confessors and martyrs were the real heroes and leaders. In this spiritual battle against wickedness and demons, Christians participated in a grand spectacle watched by God and the choirs of angels.
Despite the debate, after 173 CE, the legions began recruiting Christians for service, and many joined. Alex Bellamy believes that a combination of factors prevented Christians from joining the legions earlier. In addition to the pacifism of leaders like Origen and Tertullian, Christians faced official persecution and saw Rome as the Antichrist. As Tertullian argued, Christians also faced the problems of idolatry and forced worship of pagan deities if they joined the legions. Finally, many Christians believed that the Second Coming of Christ was imminent. This eschatological view might cause Christians to focus more on spiritual matters than earthly ones. After 173, the professionalization of army service, the danger to peace posed by barbarian incursions, and diminishing belief in the imminent return of Christ increased the willingness of Christians to serve. By the time Constantine ordered his soldiers to decorate their shields with the Chi Rho symbol before the Battle of Milvian Bridge, Christians had been serving in the legions for almost one hundred fifty years.
Christians continued to attempt to define their relationship with the use of force. At the end of the second century CE, Clement of Alexandria wrote that military service was acceptable for regular Christians. However, those labeled “Gnostics” or leaders and teachers should avoid military occupations due to the higher level of spiritual striving. Although Clement wrote in an era roughly contiguous to that of Tertullian and Origen, his attitude toward military service was radically different. James Turner Johnson argues that the difference lay in Clement’s understanding that the Second Coming of Christ was not imminent, and that the Roman Empire provided the best hope for peaceful existence.
Two centuries later, Ambrose, Bishop of Milan adapted Cicero’s criteria for a Just War to Christianity, to which his student, Augustine of Hippo added a requirement that combatants respect the rights of professional clergy. Ambrose believed that the Christian obligation to love one’s neighbor included protecting them from physical harm. Christians could use force to protect their neighbors from attack if it was the only way to do so. Ambrose provided Christians with two justifications for conducting wars. Basing his argument on descriptions of war in the Old Testament, Ambrose claimed that war was occasionally necessary to protect innocents. Otherwise, Christians could only participate in wars for self-defense, or at God’s command. It is important to understand, however, that Ambrose contended that warfare was the sole province of the state – individual Christians were unable to kill to protect themselves.
Building on the work of his mentor Ambrose and of Cicero’s first century CE work, Augustine further developed a framework of the conditions necessary for a just war. The key component of his guidance regarding the use of force is that of having the right intent. Like earlier Christian commentators, Augustine rejected killing in self-defense by the individual. When an individual killed in self-defense, he killed in order to protect earthly goods in opposition to the will of God. This was done not out of love of God, but out of love for material things. The selfish nature of this act made it unacceptable.
Defending the lives of other people or to maintain peace was a different matter. If the individual had to kill to protect others, as long as malice, hatred, or personal gain is not present, then the killing is not a sin. The act of killing must be one of Christian love, not of self-gain. It is in this light that Augustine provides justification of warfare based on three primary criteria for the conduct of a justifiable war: a just cause, legitimate authority, and right intention. The only acceptable rationale for conducting war is to either preserve or to restore peace. This means that Christians may not engage in aggressive warfare, but only in the manner of defending their own state, or that of another innocent party. Earthly peace for the contemplation of the divine and helping others are the highest goods in Augustine’s cosmology. The release of lust, hatred, and greed in war makes it his highest evil. Since the intentions of wars undertaken for these tasks are not those of Christian Love, Augustine absolutely prohibits wars of conversion of pagans or destruction of heretics and pagans.
Just wars may be conducted under legitimate authority. Augustine develops this portion of his theory of war through his examination of sin. He believed that individuals do not have completely free will. The sinful part of their nature leaves them free only to choose which sins they will commit. Since people cannot choose not to sin of their own accord, political authority is required to reduce and punish sinful acts. This requires a coercive force ordained and guided by God. Utilizing Paul’s argument in Romans 13, Augustine contends that even unjust regimes are the work of God, perhaps as punishment for the sins of the people. The ruler’s status as the divinely ordained instrument of God, he has the authority to fight wars. Because they kill at the command of the ruler, soldiers are not committing murder. Under these circumstances, Augustine argued, not killing was both treason and sinful.
Augustine’s conception of just wars stemmed from the overarching importance of right intent in all actions. Nowhere was this more important in how to wage a war once a legitimate authority embarks on one. Both the decision to go to war and the decision of how to wage that war must be made out of love for God, not out of love for earthly things. Right love is only possible through the grace, a gift from God to the undeserving and sinful individual. God’s gift of grace allows people to do good in the world through its power, which is the only possible means to overcome the humanity’s inherently sinful nature. This allows rulers the possibility of fighting a just war, but does not guarantee that all wars that Christian rulers wage are just ones.
In order for a war to be just, the ruler must act out of right love, not only for his people, but also for their enemy. This requires that the ruler understand his own limitations, and work to uncover the motives of the enemy in order to find a just resolution short of war. Augustine further argues that rulers must be extremely careful not to proclaim that he is conducting the war out of love, as doing so is the mark of Pride. By falling victim of the sin of Pride, the ruler shows that he is acting not out of right love, but for sinful reasons.
During the centuries of turmoil following Constantine’s legalization of Christianity in 313 CE, Augustine’s doctrine of Just War, developed later in the century, assumed a more important place in the lives of many European Christians than the original Christian doctrine of pacifism. The inherently defensive orientation of Augustine’s Just War theology would seem to limit military conflicts involving Christians in Europe, this, however, was not the case.
Once Roman Christians adopted the concept of heresy at the Council of Nicaea in 313, and the religion later became wedded with the state, any conflict between individuals or groups and the official state religion became “defensive” in nature. It is evident from his specific abolition of war for religious purposes that Augustine was aware of the potential abuse of this relationship. One of the side effects of Constantine’s adoption of Christianity and insistence that its tenets be formalized in order to enhance the stability of the Roman Empire and Augustine’s theology is the development of an intolerant strain of religious thought among some groups of Christians. The combination of Roman political intrigue and Christianity had fatal results.
Intolerance for other views among Christians is evident in fourth century mob violence in Constantinople. H.A. Drake argues that despite early Christian tolerance for other religions, the growth of Christian intolerance is an outgrowth of monotheistic rejection of other forms of worship. This is particularly true after Constantine’s conversion, which began the process of codifying Christian belief and aligning the faith with the state. After the development of the concept of heresy, political factions made use of Augustine’s theory of coercion, based on Luke 14:16-24’s depiction of the propriety of forcing others to accept one’s own will, to enforce theological agreement.
The cooption of theology for political ends made use of Augustine’s use of the traditional Christian ideal of an unending battle against evil on Earth. Drake contends that Weber and Freud provide important insights into how and why this occurred. Weber argues that even after it became the dominant religion, Christianity kept the texts discussing violence toward evil as a part of its intellectual framework of striving for God. At the same time, Freud argues that the Christian message of universal love leads many believers to deny the right of others to disbelieve. Given the alignment of state and religion after Constantine, this inevitably led to religious violence.
In this light, heresy becomes a significant problem for many orthodox Christians, particularly in the hierarchy and the government. Since outsiders could not discern the difference between heretical theology and orthodoxy, heretics posed a danger to the status quo, and to the peace and stability of society. By defining heretics as the tools of Satan, sent to lead good people astray, orthodox theologians were able to motivate both monks and rulers to move against them. Drake believes that this need to eliminate the legitimacy of alternate beliefs is the key to the development of intolerance in early Christianity. Pagans became a second target of Christian intolerance only after Julian reinstates blood sacrifices in 361 CE. Christian extremists used the examples of Julian and Diocletian (244-311) to show the threat to security posed by a non-Christian state. Enemies of the state and the development by Pope Gregory VII the outlines of a Christian doctrine of Holy War, which his successor, Urban II relied on to launch the First Crusade in 1095.
The Muslim conquest of North Africa, the Near East, and Spain significantly contributed to both the intolerance and willingness to fight for religious reasons among Western European Christians. In 850 CE extremist Christians in Cordova revived the ancient practice of voluntary martyrdom when the monk Perfectus scurrilously denounced Islam in front of witnesses. Despite receiving clemency after a first offense, repetition forced the local Muslim government to execute him. After Perfectus’ execution, other Christians who could not tolerate the idea of religiously heterogeneous societies formed separatist communities, and embarked on an aggressive anti-Muslim campaign based on forcing the Muslim authorities to execute them. Karen Armstrong argues that this movement originated in a resurgence of millenarian or eschatological ideas. Even after the movement died out with the execution of its leader, Eulogio, in 859 CE, it created a desire among many Andalusian Christians for a separate Christian identity.
This new ideal for a separate and uniquely Christian identity among Christians in Muslim Spain combined with the belief of other Europeans that the Iberian Peninsula was still part of Christendom to move from the Augustinian conception of a just war as primarily defensive to one of an offensively oriented Holy War of conquest. The reconquista witnessed the first apparent combination of pilgrimage with warfare, as soldiers embarking on the liberation of Spain first stopped at the shrine of Santiago de Compostello in northern Spain. In the centuries leading up to the first millennium, the Church portrayed war against Muslim rule in Spain as a just reaction to the Muslim incursion. However, did not yet advocate any spiritual benefits for participation.
Despite the Church’s enthusiasm for the reconquest of Spain, it still viewed warfare and violence as
inherently sinful, even in cases of Just War. At the end of a war, soldiers were required to confess and perform penances before they could fully rejoin the life of the Church. The official attitude toward violence, then, is in conflict with one of the Church’s goals in Europe – to drive Muslims out of Spain. However, the war in Spain did provide a significant benefit for the Church’s attempts to control the level of armed violence in Europe by providing an outlet for the urges of Europeans with aggressive tendencies. The Church’s approval not only aided Spanish Christians with the effort, but also provided the Church a way to maintain peace within Europe that failed tenth century efforts to curtail private wars did not. J.J. Sanders argues that the failure of the Truce of God and Peace of God led directly to the development of Crusading ideology when the Church chose to redirect Europeans’ martial spirit toward external threats. Pope Alexander II’s offer of an indulgence in 1063 CE to those who fought against the Moors created an even tighter connection between war and the Church.
All of the traditional underpinnings for Crusade are thus in existence by 1063 CE, even if they are not fully articulated as a package – the combination of war and pilgrimage, the granting of indulgences to soldiers who fight in the prescribed manner and location, and the definition of wars of conquest as defensive when aiding other Christians against pagans or heretics. However, these disparate items still needed additional cultural developments, the efforts of two influential Popes, and a new external threat to excite Christian Europe before they could form a coherent ideology of Crusade. The short span of only two decades provided all three components.
Karen Armstrong identifies two important cultural changes occurring in Europe around 1000 CE. The first of these is a feeling among Western Europeans of spiritual divorce from the holy sites of the Eastern Mediterranean. This led to an emphasis on pilgrimages to Jerusalem, including a bizarre incident in 1009 CE, in which Count Fulk of Anjou bit off a piece of tone from the tomb in the Church of the Holy Sepulcher. Fulk and other Western Christians believed in the literal truth of Biblical stories, leading to their veneration of relics and visits to holy sites. The emphasis on pilgrimage embodied in this played an important part in the preaching of the Crusade in 1095.
A second critical cultural development is the revival of the Sibylline Prophecies around 1000 CE. The prophecies claimed that a Western Emperor would be crowned in Jerusalem and lead the fight against the Antichrist. This belief spawned the two great pilgrimages of 1033 CE and 1063 CE. Armstrong asserts that Urban II’s decision to preach the Crusade in 1095 is part of this pattern of pilgrimage based on the Sibylline Prophecies.
More changes in Europeans’ views of both Muslims and of warfare were also underway. The epic Song of Roland contains negative propaganda against Muslims, accusing them of not worshipping God, but Apollo. It also portrayed a new ideal of Frankish knight in Roland, who a ferocious warrior rather than an intelligent or wise one. This combined with descriptions of Muslims as idolaters who worshipped images of Mohammed to define Muslims as pagans, which led to the creation of Muslims as a cultural enemy for European Christians. Armstrong further argues that the identification of Muslims as a pagan threat led Western Europeans to revisit Joshua’s holy wars of extermination against pagans in the Bible, which may explain some of the brutality Crusading armies engaged in when fighting non-believers.
With this cultural foment in Western Europe, Pope Gregory VII received a request for aid in the aftermath of the Byzantine defeat by the Seljuk Turks at Manzikert in 1071 CE, and attempted to raise an army to aid the Byzantine Empire. Gregory had two goals in requesting aid from European nobility. The first goal was to pacify Norman lords in southern Italy who were steadily pressing north toward the Papal States. The second goal was to relieve Constantinople in the face of the Seljuk threat. To encourage participation, Gregory claimed that volunteers would receive spiritual rewards.
It is a mistake to assume that Gregory thought that warfare was a positive good, or that he offered soldiers operating under Papal authority the same type of indulgence that historians associate with the Second Crusade. In assigning penances to knights, Gregory insisted that until the penance was complete, the penitent knight could bear arms only for defense or to fight Muslims. The nature of the penances themselves focuses on the purity of the individual and in the true conversion of the sinner before allowing them back into the full communion of the Church. A Papal decree of 1078 CE made it impossible for knights performing penances to bear arms at all, and further asserted that fighting was not possible without sinning. The combination of these strictures meant that despite Gregory’s call to arms to support the Byzantines, knights could not earn a living within the confines of the Church.
However, when it came to achieving his own purposes, Gregory was willing to resort to Church-sponsored violence. When asking for volunteers to assist Byzantium, his letter to all Christians asserted that Christian Love demanded a reaction from European Christians to defend Greek Christians from Muslim invaders. Based on this, it seems obvious that Gregory intended his call to arms as a mission of mercy, not a holy war. Taken in the context of Gregory’s efforts to increase Papal supervision of warfare, this represents a new moral aspect to European wars.
Gregory VII was unable to organize an expedition for the relief of Constantinople, but neither the problems of war, nor the Muslim threat to the Byzantine Empire died with him. Urban II took up these issues near the end of his Papacy when the Byzantine Emperor Alexius II requested aid to ward off the incursions of the Seljuk’s Turcoman subjects. When Urban preached the First Crusade at the Council of Clermont in 1095, he called on knights to liberate Christians from Muslim rule. In doing this, he requested not just aid to Byzantium, but for the conquest of Jerusalem. Part of Urban’s message was the use of grossly inaccurate anti-Muslim propaganda similar to that used by Gregory VII two decades earlier.
Urban went significantly beyond the foundation laid by Gregory and his predecessors in promoting the expedition to Jerusalem. Rather than calling for an expedition to protect the lands of St. Peter, as Gregory had, Urban called for an army of Christ to liberate the Jerusalem and make a pilgrimage to the Holy Sepulcher. His language, along with the requirement for those who took the cross to make a vow based on that of a pilgrim’s vow, lead many historians to argue that Urban created an armed form of pilgrimage. In reality, Urban is creating a new type of Church-regulated warfare in which the war itself is considered the penance required for remission of sins. This is clear from the language he uses to describe the military expedition: “labor”, “ifer”, and “expeditio” are used, not the “peregrinatio” commonly associated with the act of pilgrimage. This is a clear indication of Urban’s understanding of the division between the military nature of the First Crusade and that of the pilgrimage conducted by non-combatants.
Urban developed this interpretation of war as penance from Augustine’s equation of the act of punishing in the role of justice with being persecuted, which makes fighting for God righteous. Urban also justified this stance by arguing that the journey to Jerusalem and fighting on behalf of other Christians with Jesus’ burden in carrying the cross through the streets of Jerusalem before the Crucifixion. In this way the Crusaders were emulating Christ’s ultimate sacrifice for mankind, and fulfilling the penance for their sins. This still did not earn Crusaders remission of their sins unless they undertook the journey with the right intention. Those who went to Jerusalem seeking fortune and glory could not receive forgiveness for their sins because they did not fight out of Christian Love for the Christ, or to defend fellow Christians.
In terms of future European wars, the Urban’s Crusading ideology may not be the most important ideological result of his preaching. In preaching the Crusade, Urban broke with many traditional Western European Christian understandings of war. Before 1095, the image of war was predominantly negative. Clerics could not engage in battle, and lay people endured penances even for fighting defensive wars. Once papal sanction removed the negative aspects of war from Europeans understanding of war, especially against unbelievers, those wars became more brutal in nature.
The relationship between Christianity and violence through the end of the eleventh century is a complex and changing one. It is clear that Christians were quickly forced to deal with the difficult issue of living in a dangerous world and balancing the acts needed to survive with the sometimes-contradictory dictates of both the New and Old Testaments of the Bible. Christianity’s interaction with Rome before and after it became a dominant religion further changed its stance on war from the complete pacifism of Early Christian leaders to the belief that it was acceptable to defend others from aggression as a responsibility of Christian Love. While the Crusading ideology viewed itself as a defensive one, in which soldiers defended Christ and Christians from the aggressive depredations of the allies of Satan, it was developed alongside aggressively misleading portrayals of the intended enemy. This calls into question whether the Crusading ideology of Gregory VII or Urban II was truly based on the twin concepts of Christian Love and right intention, or whether it they based it on more earthly considerations.
 Bellamy, Alex J. Just Wars: from Cicero to Iraq (Cambridge, Polity Press, 2006), 18.
 Ibid, 19.
 Arthur F. Holmes, “The Just War,” War: Four Christian Views, ed. Robert G. Clouse (Downers Grove, IL: Intervarsity Press, 1991), 122.
 John Langan, S.J., “The Western Moral Tradition on War: Christian Theology and Warfare,” Just War and Jihad, eds. John Kelsey and James Turner Johnson (New York: Greenwood Press, 1991), 79.
 Harnack, Adolf. Militia Christi, trans. David McInnes Gracie (Philadelphia: Fortress Press, 1981), 36.
 Ibid, 18.
 Ibid, 40.
 Ibid, 14.
 Langan, 85.
 Bellamy, 21.
 Harnack, 45-48.
 Bellamy, 23.
 Ibid, 22.
 Harnack, 55-60.
 Bellamy, 22.
 James Turner Johnson, “Historical Roots and Sources of the Just War Tradition in Western Culture,” Just War and Jihad, eds. John Kelsey and James Turner Johnson (New York: Greenwood Press, 1991), 9.
 Bellamy, 24.
 Bellamy, 26.
 Stevenson, William R. Christian Love and Just War (Macon, GA: Mercer University Press, 1987), 35.
 Stevenson, 11.
 Bellamy, 26.
 Madden, Thomas F. A Concise History of the Crusades (New York: Rowman and Littlefield, 1999), 2.
 Stevenson, 63.
 Stevenson, 69.
 Ibid, 77.
 Ibid, 89-93.
 Ibid, 106-108.
 Drake, 4.
 Ibid, 13.
 Ibid, 28-31.
 Ibid, 35.
 Armstrong, Karen. Holy War (London, MacMillan, 1988), 33.
 Ibid, 34.
 Madden, 4.
 J.J. Sanders, “Crusade as Holy War,” The Crusades: Motives and Achievements, ed. James A. Brundage (Boston: C. Heath and Company, 1964), 56.
 Ibid, 57.
 Armstrong, 43.
 Ibid, 44.
 Munro, Dana Carleton, “The Western Attitude toward Islam during the Period of the Crusades,” Speculum 6, no. 3 (1931), 331.
 Armstrong, 47.
 Munro, 331.
 Armstrong, 47.
 Brundage, James A. The Crusades: A Documentary Survey (Milwaukee, WI: Marquette University Press, 1962), 8.
 H.E.J. Cowdrey, “Pope Gregory VII and Bearing Arms,” Montjoie: Studies in Crusade History in Honour of Hans Eberhard Mayer, eds. Benjamin Z. Keder, Jonathan Riley-Smith, and Rudolf Hiestand (Aldershot, Hampshire: Varorium, 1997), 28.
 Ibid, 26.
 Brundage, 9.
 Madden, 7.
 Cahen, Claude, “Introduction to the First Crusade,” Past and Present no. 6 (1954), 9.
 Madden, 8-9.
 Jonathan Riley-Smith, “The First Crusade and St. Peter,” Outremer: Studies in the History of the Christian Kingdom of Jerusalem, eds. B.Z. Keder, H.E. Mayer, and R.C. Smail (Jerusalem: Yad Izhak Ben-Zvi Institute, 1982), 52.
 Madden, 11.
 Jensen, Janus Moller, “Peregrinatio sive expeditio: Why the First Crusade was not a Pilgrimage,” Al-Masaq: Islam & the Medieval Mediterranean 15, no. 2 (2003), 122.
 Janus Jensen Moller, “War Penance and the First Crusade,” Medieval History Writing and Crusading Ideology, eds. Tuomas M.S. Lehtonen, Kurt Villads Jensen, Janne Malkki, and Katja Ritari (Helsinki: Finnish Literature Society, 2005), 57.
 Ibid, 125.
 Brundage, 20.
 Coates, A.J. The Ethics of War (Manchester: Manchester University Press, 1997), 107.
 Ibid, 106.