As evidenced by the (initially) purely doctrinal intentions of Luther's suggested changes, the Reformation began as an attempt at ecclesiastical reform from within, which was not a new idea. Medieval Europe experienced its fair share of reform movements, most notably after the Investiture Controversy of the 11th Century, an open and explicit conflict between the pope and the Holy Roman Emperor. The thrust of reform, in that case, centered on popes and clerics trying to protect the church from lay influences in order to preserve purity. Reform continued throughout medieval Europe, though on a much smaller scale. In the fourteenth century, a strong wave of Anticlericalism was spurned after the crisis of the Black Plague. As the gap between laity and clergy narrowed out of the necessity to fill vacant positions, a new conception of the church's role arose. Popular sentiments suggested that only scripture was essential and the church was not a required mediator (these sentiments would be later echoed by Luther). .
Wavering faith in the authority of the Catholic Church grew after the Great Schism of 1377 and people such as Eckhardt and his mystics lead paths of alternative experiences in Christianity, but these efforts never led to such a public overarching propaganda campaign as the Reformation. In the meantime, Counciliarism kept strains of anticlericalism alive in Europe. Culminating at the time of Luther, the failure of the inexperienced clergy to perform their duties properly and allegations of corruption within the church, particularly surrounding the selling of indulgences, spurned an increased amount of public criticism concerning the universal church and its abilities. The Reformists simply took advantage of this overarching public sentiment. Thus, from many older historical trends of reform, the concrete division of the Catholic Church emerged. The Reformation, therefore, was as much a continuation as a variation on a familiar historical melody; it was simply the enduring spirit of reform carried out to drastic new levels.
