There were of course other areas in which the power of the papacy was made manifest between 1100 and 1300. One that must not be overlooked was crusading. Though Christian Holy War had roots in the era before the rise of the Gregorian papacy (in the Christian imperial ideology of Charlemagne and his forced conversion of the Saxons, for example, as well as in the Peace of God and Truce of God movements of the tenth and early eleventh centuries),
Gregory himself took sacred violence to a new level by vowing personally to lead an army to liberate Christians in the East and reunite the Roman and Eastern churches.44 Even before that, in 1063, Alexander II had offered remission from sins to those participating in the reconquest of Spain.45 In the last years of the eleventh century a papally summoned crusade was finally launched, the improbably successful First Crusade. In the next two centuries, proclamation by a pope was a virtual sine qua non for Holy War, whether directed against Muslims, Cathars, pagans or the political enemies of Rome. Only the apostolic see could bestow the expansive and much coveted crusade indulgence. Over the course of the twelfth century, this doctrine came to be understood as complete remittance of all penalties owing to sin, on earth and in purgatory. Crusading, in the words of Innocent III, afforded 'full forgiveness of sins'.46 Once a crusade was launched, however, the pope had very little control over its conduct. Innocent thundered against the misguided holy warriors of the Fourth Crusade who pillaged Christian Constantinople and offered thereby 'only an example of wickedness and works of darkness',47 even as the crusaders were reassured by their advisors that the war was 'droite et juste'.48
World History
