アルビジョア十字軍
Raphael Lemkin, who in the 20th century coined the word "genocide", referred to the Albigensian Crusade as "one of the most conclusive cases of genocide in religious history". Mark Gregory Pegg writes that "The Albigensian Crusade ushered genocide into the West by linking divine salvation to mass murder, by making slaughter as loving an act as His sacrifice on the cross." Robert E. Lerner argues that Pegg's classification of the Albigensian Crusade as a genocide is inappropriate, on the grounds that it "was proclaimed against unbelievers ... not against a 'genus' or people; those who joined the crusade had no intention of annihilating the population of southern France ... If Pegg wishes to connect the Albigensian Crusade to modern ethnic slaughter, well—words fail me (as they do him)." Laurence Marvin is not as dismissive as Lerner regarding Pegg's contention that the Albigensian Crusade was a genocide; he does however take issue with Pegg's argument that the Albigensian Crusade formed an important historical precedent for later genocides including the Holocaust.