If there's one thing I can never quite grasp it's theology, so the Cathars a a bit of a mystery to me too. However it seems that they were a religious sect that flourished in southern France and northern Italy in the 12th and 13th centuries. They believed in dualism (it says here) and the main objection that the Church had against them was that they rejected the incarnation of Christ, instead asserting that he was an Angel. They also foreswore sexual intercourse so I'm surprised they lasted as long as they did !

"The beliefs of the Cathars were so radical that they were hardly Christian at all: they held that there were two Gods, the God of the spiritual world and a God who had created the material world in which the soul was imprisoned.  To free their souls, the Cathars tried to give up everything of this world.  They did not eat meat, milk, or eggs, abstained from sexual relations, denied the Trinity and renounced the Church."

from The Atlas of the Crusades, edited by Johnathan Riley-Smith.  

 

Pope Innocent III procalimed a Crusade against them in 1208, it lasted from the spring of 1209-1212.  A second was preached and lasted 1213-1229.    The Cathar region wasn't conquered until Count Raymond VII sued for peace from King Louis in 1229.  Then came the Inquisition, foreign settlers, and the dispossession of the Cathar nobles. The last PURE (Cathar priest) was burned alive shortly thereafter.

 

The Cathars COULD have sex, but only for the purpose of procreation

A Crusade is a sort of Christian Holy War and could be called against almost anything or anyone. There were Crusades against the Mongols and the Russians, even against heretical Christian sects.

Cathrs were one of many groups of men and woman who wanted Chruch reform during the middle ages.  They were influenced by the works of the Gospels and their own feeling of dis-location withing the mainline of the Chruch.  Often they took more of a gnostic approach to belief, called for reforms and questioned the real belief of the Popes.  Many of these groups believed that a radical poverty was to be lived.  This was, for them, the real way of the Apostles.  This call to poverty was a threat to the establishement who lived a very rich life.

 

One reason Francis of Assisi was so successful in his reform was that he learned a lesson for these early groups and pleadged that the Friars would remain faithful to the Pope and Bishops.

Frank