Abstract/Summary

Papal letters were issued for the specific purpose of authorizing and encouraging the Albigensian crusade; their purpose was never to inform the reader or listener about the nature of Cathar beliefs or their origins. Indeed it is very likely that neither Innocent III nor Honorius III knew very much about the dualist heresy against which they authorized their crusade. In order to find detailed information on what this prominent group of heretics, popularly called 'Cathars', did and did not believe, who they were and where their beliefs and practices originated, we must look for answers not in papal documents but in other primary sources from the period.