Without lifting a sword, the Cathars posed a threat to Catholicism greater than the Muslims or Jews—or so the Church believed. The Cathars believed that matter was essentially evil—especially the human body—and that the material world had to be transcended through a simple life of prayer, work, fasting, and nonviolence. Though they radically departed from certain traditional Christian beliefs, the Cathars still believed themselves to be the heirs of the true heritage of Christianity. They completely rejected the Catholic Church and all its opulent trappings, regarding it as the Church of Satan; Cathar services and ceremonies, by contrast, were held in fields, barns, and people's homes.

The Cathars found widespread popularity among peasants and artisans. They respected women, who played a major role in the movement. Alarmed at the success of Catharism, the Church began the Inquisition and launched the Albigensian Crusade to exterminate the heresy. The Albigensian Crusade was the first Crusade to be directed against fellow Christians and was also the first European genocide. Today, the mystique surrounding the Cathars is as strong as ever. Their myths and complete history are examined here in The Cathars—the compelling true story of this once peaceful religious sect.