C rusade is a military operation with religious purpose intended to go out of the" error" the parts of France subjected to the paganism or in the heresy. The Pope appeals to the crusade, chooses its destination and names the enemies to slaughter or to convert. He is represented by one or several legates who steer expedition with the military leaders. Every person who leaves for a crusade profits by privileges: fiscal exemptions, possibility to receive part of booty or lands, indulgences for committed sins, protection of the Church on his possessions: nobody can appropriate the possessions of a crusader during its absence (this point explains the fast submission of Raimond VI in the crusade in 1209). Crusade against Albigeois is the first crusade who affects Christian Lords whose most of the subjects were Christians, in a Christian Kingdom. Naming the enemies is difficult all the more as Cathars, with the exception of "Parfaits", do not distinguish themselves from others. the The Lords who tolerate Catharisme on their lands are first attacked. It creates a crisis with the crusaders who act for religious motives or only to make quickly fortune, and the people from south of France who see in the crusade only a military expedition fighting against the notions of tolerance, of respect for the individual, curtly against the Southern civilization. The idea of crusade is going to remain, in a more and more artificial way, until the XV ° century. The cross which, in the beginning, is worn only on the shoulder (as the cross carried by the Christ), becomes then systematic for those who have no heraldry, becoming, during the Guerre de Cent ans, t a simple sign of recognition to distinguish French soldiers from English soldiers.