Dualist religion based on the principle of Good and Evil and taking its inspiration from oriental sources (Iran). Catharism appears in Europe around the second century.
The Cathars wanted to restore Man with godly purity. They deny the divinity of Christ, reject the participation of the Church in the temporal world. The hierarchy in the Cathar church differentiates "Croyant" (believers) from "Parfaits" (perfect ones) who directed the believers through their exemplary and ascetic life - (chastity, humility, patience).
Catharism is established in the Upper-Languedoc, in towns such as Albi, Toulouse, Agen, Carcassonne.


In 1209, the assassination of the Papal Legate, Pierre de Castelnau, leads to an offensive called the Albigensian Crusade ordered by the Pope Innocent II. The Cathars resist the persecution of the Simon de Montfort army and the juges of the Inquisition. They are pursued and besieged in fortified castles.
The last resisting castle, Montsegur, falls after ten months of resistance, in 1244. All the occupants, refusing to renounce their religion, are burned on a stake.