What were the motives of the crusaders during the first crusade?

The Crusades were a series of religious and political wars fought between 1096 and 1291 for control of the Holy Land. Pope Urban II initiated the First Crusade (1096-1102) in order to aid the Christian Byzantine Empire, which was under attack by Muslim Seljuk Turks. As a result of this crusade, Europeans captured Jerusalem in 1099. Muslims quickly unified against the Christian invading and occupying force and the two groups battled in subsequent wars for control of the Holy Land. By 1291 the Muslims firmly controlled Jerusalem and the coastal areas, which remained in Islamic hands until the twentieth century. The crusading movement involved men and women from every country in Europe and touched upon almost every aspect of daily life, from the Church and religious thought, to politics and economics. It also found its way into the arts, as patrons and artists from diverse backgrounds and traditions were brought together to create new forms of expression. Frescos, mosaics, sculptures, and even coins reflected a blend of Western (Latin/Catholic) and Eastern (Byzantine/Eastern Christian) traditions. Crusaders appeared in histories as well as in French and German epic poetry from the twelfth century, such as the Chanson d’Antioche, an account of the 1098 siege in Antioch. The crusading movement involved men and women from every country in Europe and touched upon almost every aspect of daily life, from the Church and religious thought, to politics and economics. Christians understood the Crusades as a path to salvation for those who participated. As the French monk Guilbert of Nogent wrote in his twelfth century chronicle of the Crusades, "God has instituted in our time holy wars, so that the order of knights and the crowd running in its wake ... might find a new way of gaining salvation. And so they are not forced to abandon secular affairs completely by choosing the monastic life or any religious profession, as used to be the custom, but can attain in some measure God’s grace while pursuing their own careers, with the liberty and in the dress to which they are accustomed." Those who "took up the cross" were recipients of both spiritual and earthly rewards. The spiritual reward was the indulgence, or the forgiveness, of sins. The earthly rewards included plunder from conquest, forgiveness of debts, and freedom from taxes, as well as fame and political power. Crusaders did not only fight for control of the Holy Land; they also worked to secure the Church’s power in Europe. Like the wars against the Muslims, these conflicts were promoted by various popes in Christ’s name and led by crusaders who took vows and received special privileges and indulgences. The "enemies" of the Church in Europe included people who were not Christians. It also included Christians who were labeled heretics, that is, people who challenged the official teachings of the Church or who questioned the pope’s power and authority. Millions of people, Christian and non-Christian, soldiers and noncombatants lost their lives during the Crusades. In addition to the enormous loss of life, the debt incurred and other economic costs associated with the multiple excursions to the Middle East impacted all levels of society, from individual families and villages, to budding nation-states. The wars also resulted in the destruction of cities and towns that lay in the crusaders’ wake. In his Decline and Fall of the Roman Empire, Edward Gibbon refers to the Crusades as an event in which "the lives and labours of millions, which were buried in the East, would have been more profitably employed in the improvement of their native country."