The Catholic Church was one of the most powerful entities in Christian Europe in the mid-late medieval period. Commanding the fealty of the majority of Europe, the Church was able to muster vast swathes of men to partake in the religious wars known as ‘The Crusades’. Traditionally, these Crusades had been used to unite men from Christian nations against Islamic forces, first against the Saracens who had conquered Jerusalem, and later the Muslims of the Iberian Peninsula during the centuries-long Reconquista. Under the influence of Pope Innocent III and his successors, however, the limits of what the Pope could call Crusades against began to expand, first to a broader definition of the enemies of Christendom, and later, perhaps more cynically, to any enemies of the papacy, regardless of their creed.
Ascending to the papacy at the end of the twelfth century, Lotario di Segni, who would take the name Innocent III, was arguably the most powerful medieval pope of them all. Presiding over the Catholic Church at the height of its power, Innocent sought to greatly increase the temporal power of the Church and establish its pre-eminence over all secular nations. Although he would be responsible for a great many accomplishments during his tenure as Pope, it is perhaps in his part in the changing and expanding role of Crusades that was his most striking legacy in the centuries following his death. His firm belief in ‘papal primacy’ and his desire to increase the temporal power of the papacy, combined with the recent fall of Jerusalem to Saracen forces in 1187, made for fertile soil in which an interest in crusading could take root. He began to draw up plans for the Fourth Crusade within a year of his appointment, issuing the papal bull Post miserabile to this effect. Criticising the current state of affairs in Europe, the bull called for a new crusade to retake the Holy Land. At this time, Christian Europe was riven by civil conflict. War between England and France had broken out once again, with the papacy’s typically closest ally, the Holy Roman Empire, estranged and undergoing its own succession crisis. As a result of this, the call for a Crusade against external forces served as a papal attempt to unify the forces of Christendom against a foreign enemy, emphasising the increasingly political nature of crusading under Innocent III.
However, despite the fact that the Fourth Crusade had rampaged through Christian lands, including the port city of Zara, culminating in the sack of Constantinople, this had not been the intention of the papacy at the Crusade’s inception. Instead, it was the Cathars of Languedoc, in southern France, that would gain the dubious honour of being the first sect of Christianity to be explicitly declared the target of a Crusade by the papacy. Having been declared heretical for their dualist creed in 1176, they had long been a target of Innocent III for their defiance of the papacy. Only a minority in the region, the promise of indulgences to assuage any guilt that the Crusaders may have had about killing innocent, devout Christians alongside Cathars is a clear sign of how the Church increasingly valued the temporal power afforded by the success of the Crusade over any spiritual qualms.
This also set a precedent for a widening scope for Crusades, which went along with the growing power of the papacy in the thirteenth century and its increasing desire to involve itself in the secular as well as the spiritual realm. For the Pope, Crusades became a way to exert dominance over Christian Europe as a whole. Rather than just a unifying force as they had previously been, they swiftly became a way to remove political threats. By declaring those who had earned the ire of the papacy as heretics, this gave the Pope justification under the precedent set by Innocent III to call a Crusade against them. This was first seen little more than a decade after Innocent III’s death, in the papal conflict with the Holy Roman Emperor Frederick II of the Hohenstaufen. Differing interpretations of the ‘two swords doctrine’ that defined the relationship between the Holy Roman Empire and the papacy, with Frederick seeing them as equals who attended to separate spheres, whereas the papacy saw itself as the ultimate arbiter over both temporal and spiritual power, with any power held by the Emperor merely granted by the Pope, saw Innocent’s successors call two Crusades against the excommunicated ruler. Although these were risky ventures by the papacy, these Crusades, combined with papal machinations, ultimately resulted in the destruction of the Hohenstaufen and a weakening of the Holy Roman Empire for centuries to come, serving to remind the rest of Europe of the temporal power of the papacy and the supremacy of the Pope in matters both temporal and spiritual.
The legacy that Innocent III left on crusading was profound, with the decisions that he made influencing his successors for generations to come, though he would not live to witness the true extent of the consequences of his actions. The increasing willingness of the papacy to use Crusades to achieve their own personal goals in the name of gaining more temporal power had largely proven useful for the Catholic Church, allowing it to use these Crusades to assert its authority throughout Christian Europe, especially given the loss of all Christian lands in the Holy Land following the fall of Ruad in 1302. However, the reliance on French intervention to end the Albigensian Crusade had strengthened the French monarchy at the expense of the papacy, leaving an indelible mark on the relationship between the French Crown and the papacy. This led to France taking increasing liberties in their relationship with the Church, assured by their own strength in contrast to the other nations of Christian Europe, and by the end of the thirteenth century, this would reach a head, with devastating results for the papacy.
Henry G. Miller, History in Politics Summer Writer