As far as the traditional procedure of the church towards instructing the faithful and guarding them against the corrosion of heretical doctrines, the Albigensian Crusade represented an interruption, but so long as political and religious chaos persisted in Languedoc any other method of approach was hopeless. Now that political stability had been more or less achieved, religious reconstruction had a fair chance of success. The Cathars and Waldensians were alive and flourishing, but the support and protection of the nobility had been neutralized. Further, the political lines were no longer purely feudal. The rising power of organized citizenry, as demonstrated in town after town during the crusade, gave notice that they were a power to be reckoned with.
As sometimes happens, an administrator of lesser stature and activity may achieve more in certain areas than a more brilliant man. And so it was with Honorius III who saw an end to the Albigensian Crusade and received the active legal cooperation of the Kings of France and Aragon and the Emperor – which Innocent III did not have. The decrees of the Fourth Lateran Council now appeared in the legal codes of all three, along with their individual prescriptions of a less acceptable nature. In 1224 Frederick decreed the stake for heretics in Lombardy, but apparently the only time this edict received any attention it filed, and the official attempting to apply it very nearly lost his own life. It remained in effect a dead letter.
It is also fair to say, however, that the efforts of the past half century to deal with the problem of heresy had not achieved success. The successor to Honorius III in the papacy came to the conclusion that papal authority would have to lend support to competently trained experts circulating in the infect regions, using a uniform procedure under a centrally organized administration. The new pope, Gregory IX (1227-1241), set about to establish the Inquisition.
Albert Shannon, The Medieval Inquisition (1991)