Pilgrimage is the single most important influence on the origin and development of crusade. In fact, without the history of pilgrimage in Western Europe, it is possible the First Crusade would never have happened. Further, even if Urban II had managed to persuade significant numbers of milites to go to the Byzantine emperor’s assistance without preaching it as a pilgrimage, an ongoing tradition is unlikely to have been created. Later, Christians who stayed in the East managed to live relatively peacefully alongside Muslims. However, they had a constant need for military reinforcements and the best way to attract these from the West was to appeal to religious consciences. Therefore the new arrivals at any time were always fiercely anti-Muslim and the religious fervour of new crusaders from Europe kept up the momentum of holy war in the Holy Land, when it may have been possible to make peace. It was also largely religion that caused the divisions between Western and Eastern Christians, exacerbating the situation.  Ultimately, it was partially the link between crusade and pilgrimage that undermined crusade at the end of the thirteenth century.

In calling on Christian knights to go to the aid of their fellow Christians, Urban II’s rhetoric on behalf of what would become the First Crusade was not particularly new or revolutionary. What historians have argued was unique about the First Crusade, its most radical and defining feature, was that it was penitential. Because the penitential nature of the First Crusade made it a unique form of holy war, clerical authorities reasoned, it also required a different type of warrior. The reformed clergy thus dictated the framework for this model of warrior by borrowing in significant part from, of all places, the pilgrimage tradition. Indeed, the combatants who took part in the First Crusade were technically considered to be pilgrims and were required to take pilgrim’s vows, thus taking part in no less than an armed penitential pilgrimage. According to Robert the Monk, for example, who attended the Council of Clermont in his capacity as the Abbot of the monastery of Saint-Remi, Pope Urban II at Clermont (1095) referred to the crusade as a ‘holy pilgrimage’ (sanctae peregrinationis) and demanded the same vow from the crusaders as was expected from pilgrims.

The idea of a crusade as a form of pilgrimage was well in keeping with the notion, promoted by clerical leaders, that the anticipated hardships of the First Crusade represented a type of redemptive suffering for those who participated.

Thanne longen folk to goon on pilgrimages,
And palmeres for to seken straunge strondes,
To ferne halwes, kowthe in sondry londes;
And specially from every shires ende
Of engelond to caunterbury they wende,
The hooly blisful martir for to seke

Chaucer, Canterbury Tales, Prologue 12-17

Sermons were preached on many different occasions in the course of a crusade. Propagandists preached in order to announce new crusades as well as to recruit participants and collect money for military campaigns. Often the departure of a crusader or a crusade army was also marked by sermons. During the campaigns, the clergy accompanying armies regularly preached sermons in order to sustain the participants’ enthusiasm or to give them courage on the eve of a battle or in moments of crisis. Sermons thanking God were held after successful battles. In addition, sermons about the crusade were preached to those at home in the context of penitentiary processions and prayers in support of crusaders in the field.

In response to crusade preaching, anyone of pure heart “no longer hesitated (non dubitasset) but hastened (celeries accipere) to go voluntarily to the Holy Sepulcher.” The Franks “immediately” (protinus) sewed crosses on their right shoulders and “very soon” (iamianque) joined the armies. With a great sense of urgency, Urban, archbishops, bishops, abbots, and priests, “set out as quickly as possible… to deliver sermons and to preach eloquently.” Urban’s emotional pleas and grievances were not limited to literate chronicle propaganda. Urban put in motion a well-running propaganda apparatus to mass communicate his urgent message: retaliate immediately against the Muslim enemy. To meet the enemy, however, crusaders needed first to travel safely hundreds of miles, only then to take their chances against an allegedly most dangerous foe. The non-threatening Jews were within arm’s reach and vulnerable. Violating the so-called Augustinian doctrine of Jewish tolerance and physical protection, both the crusaders who could no longer wait to punish the Muslims in the East and “wannabe” crusaders who fantasized about doing so without actually leaving their towns, or at least felt obligated to assist the crusaders, could redirect their aggressiveness against the Jews of Europe. Thus, the attackers could have their immediate satisfaction risk-free before meeting the Muslims in the east, and those who did not plan to join the long journey could feel exonerated from any blame. These attackers enhanced their satisfaction by modeling their violent acts on the First Crusade’s propagandistic examples of Muslims’ atrocities.