A shattering chronicle of the life and death of the Cathar movement -- one of Western civilization's great tragedies. At the beginning of the 13th century, the Cathars, a group of heretical Christians, thrived across what is now southern France, but was then a patchwork of city states and principalities beholden to neither king nor bishop. The Cathars held revolutionary beliefs that threatened the authority of the Catholic Church as well as the legitimacy of feudal law: they thought the idea of Hell, indeed the entire metaphysic constructed by the Church, to be a sham; they rejected all sacraments, including marriage; they thought private property an absurd notion and that all things worldly were corrupt; they gave women religious status equal to men. Though they lived peacefully, the Cathars growing influence enraged a Catholic Church that was flexing its muscle after decades of weakness, and its powerful Pope, Innocent III. The Church recruited the forces of France, eager to expand her territory to the south, and systematically attacked the Cathars in crusades between 1209 and 1229. By the time the wars were over, the map of Europe had been rearranged, and the Inquisition -- unleashed. Full of colourful and passionate personalities, The Perfect Heresy sheds new light on the 13th century and on the timelessness of religious intolerance.