The crusades were an enterprise constructed out of inherently religious concerns; Jerusalem had been closed to Christian pilgrims and the Christian Byzantines were under threat from Muslim factions to the east. A similar trend was followed in the subsequent three major crusades: an alleged Muslim aggression would be countered by an apparently righteous Christian counter-attack. This threat was labelled by the papacy as a threat to all of Christendom and, for a population whose lives were dominated by religion, this was a very grave threat indeed. For kings and nobility religion was at once a fashionable expense and a very real subject of devotion. For the poor, the church was a place for conversation and celebration, confession and communion; with entire communities gathering there to do everything from celebrating Michaelmas to listening to a sermon condemning them all as sinners. Inevitably, religion would provide an underlying stimulus and justification for this act of violence undertaken in the name of God; but it would by no means be the only influence. As it is in today's society, money was an inescapable necessity of life and the restrictions which it imposed would play an important role in deciding the course and outcome of the crusades. Furthermore, any venture which required international cooperation, and especially one of this magnitude, would inevitably be restricted by the uncompromising labyrinth of temporal and papal politics.
Many crusaders would be whipped up into extreme religious fervour by charismatic speakers from the church. Multiple accounts attest to the strong public response to Pope Urban I I's proclamation at Clermont. Urban's impassioned plea for all men and women to take up arms in an attempt to reclaim the Holy Land would, according to historian Geoffrey Hindley, create a 'fervour of devotion' during which 'thousands of people people made a historic commitment on which their eternal souls would depend. During his speech Urban would emphasise the threat posed to all of Christendom by the Muslim incursion in the east and, at a time when everybody believed in God, the influence of this message cannot be down-played. Although accounts of Urban's speech are not entirely reliable due to the fact that no eye-witness accounts have survived and the secondary transcripts will often differ slightly in specifics, they are as close to a primary account as can be and, due to the multitude of accounts, themes can be identified and truths inferred. One such inferred truth is that the crowd at Clermont were greatly moved by Urban's speech. This capacity for religious figures to instil the European population with religious fervour was carried through to later crusades. Gerald of Wales recounts that Archbishop Baldwin managed to attract thousands of Welsh crusaders to the cause, despite the fact that he didn't speak their language. Later crusades would also be provided with additional religious impetus by the legacy of the First Crusade. Popular contemporary accounts of the First Crusade such as the epic poem ' Chanson d'Antioche ' embellish the role religion played in a crusade already full of supposed miracles and divine intervention; recounting, for example, an interaction between Peter the Hermit and God, or the story of a man who managed to walk through a fire unscathed, as though they had been fact. The Chanson in particular is important because it was written specifically with the intention of being read aloud to large audiences in their vernacular tongue meaning its religious take of history would have been exposed to a much wider percentage of the population than, say, the more sober account presented by ' Gesta Francorum '. It would seem, therefore, that individuals preaching on behalf of the church were primary instigators of the crusades. Nowhere else was the concept of a Holy War sanctioned by God himself so successfully instilled into European popular culture than through preachers acting on behalf of Papal authority. This message was compounded by popular contemporary histories of the First Crusade which almost mythologised its participants and ensured that, even after failures such as the Second Crusade, the public would continue to support the concept of 'Holy War' for centuries to come.
People at the time would also have been very conscious of their sins committed during the multitude of wars fought between and within European nations at the time. Asbridge begins his book, ' The Crusades: The War for the Holy Land ', detailing the lengths to which the ruler of Anjou, Fulk Nerra, went to in order to seek penance for the 'brutish' sins committed in defence of his county. The fact that Asbridge begins his book with this anecdote would imply that he believes the influence of penitential impulses to be significant; an interpretation accepted by many historians such as David Carpenter who argues that Richard I had a 'morbid sense of [his] own sinfulness' which compelled him to crusade. These examples seem to show how Christian nobility at the time did in fact take their religion seriously and a violent political landscape at home, a common factor throughout the period being examined, would have left many of them with an overbearing feeling of guilt and sinfulness. Poorer sections of society would not be immune from this influence either as church-goers were told that they too were all inherently sinful. This guilt would have been exacerbated by the fact that, during the 11th and 12th centuries, there was a genuine belief among much of the population that doomsday was at hand and humanity's moment of judgement was soon to arrive. At the time of the First Crusade the coming of the thousand year anniversary of Christ's death had only recently passed and the concept of an apocalypse would still very much be on the collective public conscience. During the Third Crusade the allure of judgement was even more distinct as 'many believed that the last siege of the world was at hand' and depictions of the event appeared in popular culture to be consumed by many prospective crusaders. The crusades offered an outlet for this desire for penance in a suitably spectacular fashion; all sin washed away in one convenient papal motion and their place in the afterlife all but confirmed. One writer, Jay Rubenstein, goes so far as to suggest that there is 'no rational explanation' for the enthusiasm shown by the general European population for the crusades and that it was this fear of the apocalypse in and of its self which drove the Western world to crusade. While Rubenstein does draw from multiple primary sources to support his argument, the influence of this 'apocalypticism' does seem to be overstated. Other important primary accounts are ignored and the influence Peter the Hermit exaggerated. Rubenstein is a Jewish writer and, as is shown by his assertion that 'Christianity had made the physical trappings of Judaism and the Old Testament … irrelevant', this may account for his insistence of an explanation which champions Jewish interests. Undoubtedly, religiously induced guilt and an innate sense of one's own sinfulness would have influenced the decisions of many to crusade. Fear of the apocalypse was by no means an all-encompassing dread as Rubenstein suggests, but it too would have drawn all sections of society to look inwards at their own morality and seek penance in the form of a Holy War.
Religion was an inescapable part of medieval life and its influence cannot be ignored when looking at the influences effecting a concept as inextricably tied to religion as the crusades. Recruitment played on people's congenital fears of sin and divine retribution while charismatic preachers would provide further encouragement to seek penance in such an apparently extreme fashion through the use of vivid imagery depicting Muslim atrocities and Christian suffering. These preachers would be buoyed in later years by the legendary legacy of the First Crusade; tinged as it was by the religious rhetoric applied retrospectively to many popular contemporary histories. While it is still debatable as to whether religion had the strongest influence on the outcome of the crusades; religion at the time was still a concept held as sacrosanct by much of the population and its influence was felt, in some way at least, universally across Europe.
Historian Marcus Bull suggests that 'the reasons why men went on the First Crusade were overwhelmingly ideological'. Such a statement does not take into account the true severity of the economic conditions at home, nor does it acknowledge the prevalence of contemporary writers who believed harsh economic conditions at home to be primary influences for the crusades. One such contemporary, Ekkehard of Aura, writes that 'The Western Franks were easily induced to leave their fields … now by civil war, now by famine, and again by sickness' and 'A great part of them started forth with wife and child and laden with their entire household equipment'. After a succession of violent rebellions spanning right across Europe, from the Earls revolt to the Great Saxon Revolt, the First Crusade was borne out of a violent and dangerous physical landscape. The importance of the harsh conditions endured by European peasants is compounded by the fact that Ekkehard was a very devout man, an Abbot and Monk, and as such his writing focuses heavily on the religious influences of the crusades. Even so, he goes out of his way to comment on the aforementioned poor living conditions in France. He does make some attempt to justify events within a divine framework (claiming many were encouraged to crusade when 'prophets appeared among them') but the fact that he mentions the influence of economic conditions in their own right at all gives some indication of their importance. The prominence of this economic influence would not be sustained throughout all subsequent crusades, however, and the peasant pilgrim would begin to be sidelined by crusade leaders in favour of building a more professional army. The decision to travel by boat during the Third Crusade 'drastically curtailed the ability of poor, ill-equipped, non-combatants to follow the crusade'. The economic restrictions of poverty destroyed the prospect of crusading for thousands of peasants: an undeniably strong influence. In addition to this the papacy appeared to be moving away from a policy of making the crusades as accessible as possible and towards one which emphasised recruitment of the wealthy. In his decree at Clermont, Urban urged his followers to 'persuade all people of whatever rank … to destroy that vile race from the lands of our friends', ensuring wealth would not be a barrier to fulfilling crusading vows. In contrast, papal taxes such as the Saladin Tithe during the Third Crusade favoured the wealthy, with landlords and land owners being rewarded while the poor often had so little money that some were unable to join the crusade at all. It may be that the papacy were becoming more interested in exerting influence over the powerful European nobility and to do this they would need to focus resources on rewarding the wealthy rather than catering to the poor.
For the Kings and nobles who took part in the crusades the potential for economic gain was limited. Rather than offering a chance for material fulfilment as was the case for some common crusaders; organising and participating in a crusade was, for most nobles, incredibly expensive. There was some opportunity for economic enrichment as every time a major stronghold, city or even island was captured, any moveable wealth would be removed and physical assets sold; with proceeds going straight back into the coffers of the crusade. Who exactly received this wealth would change between crusades but one constant remained: this wealth would serve only to facilitate the continuation of the crusade – surplus was infrequent and at the best of times an inconsequential perk. In fact, the fundamental necessity of 'covering costs' would take western crusaders in directions at times apparently contrary to their ultimate goals. Richard I would invade Cyprus, a costly venture which would anger the pope as Cyprus was officially Christian territory. Richard would quickly sell the land, however, and used the money to buy more supplies for his crusade, lending credence to Dan Jones' assessment that 'Richard was more concerned with hard cash than enduring overlordship'. Economics were able to direct the course of the Third Crusade by encouraging Richard to abandon conventional religious ideals in favour of conquest for money.
 Hatcher, J. ' The Black Death ' 2009. Weidenfeld & Nicolson.
 Hindley, G. 'The Crusades'. 2004. Robinson, London. pp.18
 Thorpe, L. (trans.) ' The Journey Through Wales and the Description of Wales'. 1978. Penguin Books.
 Sweetenham, C. (trans.) ' The Chanson d'Antioche: An Old French Account of the First Crusade ' 2016. Routledge.
 Asbridge, T. ' The Crusades: the War for the Holy Land '. 2010, Simon & Schuster. pp.110
 The Gesta Francorum was a narrative history written by an annonymous crusader shortly after the end of the First Crusade. The information it contained was used as a source for future writers such as Fulcher of Chartes and the author of Chanson d'Antioche.
 Ibid. pp.4
 Carpenter, D. ' The Struggle for Mastery: The Penguin History of Britain 1066-1284 ' 2004. Penguin Publishing. pp.246
 https://sites.dartmouth.edu/crusadememory/2016/04/24/apocalypticism-and-the-first-crusade/ Accessed 14/08/2017
 Hindley, G. 'The Crusades'. 2004. Robinson, London. pp.122
 One notable example of this would be the ' Ludus De Antichristo ' which is said to have been performed in front of Frederick Barbarossa at his coronation.
 Rubenstein, J. ' Armies of Heaven: The First Crusade and Quest for the Apocalypse ' 2011. Hachette UK. ch.1
 Bull, M. Quoted in ' History Review of New Book ' by Drew, K.F. Summer 1994 Edition.
 https://sourcebooks.fordham.edu/source/ekkehard-cde.asp Accessed 19/08/2017
 Asbridge pp.387
 https://sourcebooks.fordham.edu/source/urban2-5vers.html Accessed 23/08/2017
 Tyerman C. ' England and the Crusade, 1095-1588' 1998. University of Chicago Press. pp.171
 Tyerman, C. ' How to Plan a Crusade ' 2016. Penguin Books. pp.145
 Jones, D. ' The Plantagenets: The Kings Who Made England ' 2012. William Collins. pp.119