Extract from the book ‘Travels through History : France” available here

Catharism was an austere religion following the gnostic philosophy of God and Satan as two separate beings – God was associated with purity and Satan with every aspect of evil. Catharism encouraged its followers to adopt asceticism and celibacy even after marriage. Those who wished to serve became Perfects (Parfaits) after a demanding ceremony called a Consolamentum. This ceremony was deemed unnatural by the Roman Catholic Church and the Pope issued a Papal bull decreeing it as sacrilegious. In 1095 the Roman Catholic Church started crusades in the Middle East. After the embarrassment of the 4th Crusade (1202 – 1204) that had ended in the Sack of Constantinople – which meant most soldiers on the Crusade didn’t reach The Holy Land – Pope Innocent III turned his attention closer to home and became particularly interested in the Languedoc, where some of the people practiced a separate sect of Christianity called Catharism.