The purpose of the study is to present a valid definition of how the struggle against the Cathars was portrayed in papal propaganda between 1179-1236. This is seen as important because of the contradictory state of research and deserves an answer. One line in the research field claims it was a genocide, another claims it was not and another line claims that the whole idea of a genocide definition in this struggle is anachronistic. This study seeks to explore how this struggle against the Cathars could be explained in its time as well as an explanation for our time.   The results shows that the main goal was to defend the Church and its unity, one sub goal was to convert and to offer opportunities for renunciation, and another sub goal was annihilation. The sources admit that both an eradication of the view if self and of the collective group were a general line. The Cathars could make an apology, if they did they escaped death. The study claims it was not a genocide because of this. But an intention was eradication. This is seen as a tenable historical definition. It´s an example of religious persecution in it´s most violent form.  The study further claims that the organization and planning were systematic in order to accomplish the goals. There are some aspects of these results that indicate that new knowledge has been presented. The society was characterized by religious intolerance, the actions of the papacy must be seen in this context.