Within a year after the adjournment of the “Great Council” as it was known, Pope Innocent III was dead. Among his many projects, he had energetically devoted himself to the solution of the problem of the spread of heresy in Languedoc and elsewhere. He firmly believed that the preaching of sound doctrine would protect the faithful on the one hand, and bring back the wandering dissidents on the other. He recognized the negligence of some of the bishops and acted forthrightly to correct it. He admonished and encouraged the diocesan clergy to live up to their priestly office, and he took measures to assist in their proper selection and training. He treated the erring compassionately, but firmly, specifying that the teachings of each heretical group should be properly indicated and that the orthodox not be labeled as heretics, e.g. some of the Humiliati. New laws he did not make. He simply codified and tried to enforce those already enacted. He added no new punishments. But his good start, particularly with the aid of the well-trained monks and friars, was interrupted and thwarted by the continuing civil disorders, and more proximately, by the murder of the papal legate, Peter of Castelnau. Thus historical forces reversed the trend, and the Albigensian Crusade brought the use of stronger measures until in a more orderly, tranquil environment peaceful spiritual procedures could be resumed once again.
Albert Shannon, The Medieval Inquisition (1991)