Albigensian Crusade.

The Albigensians were a ascetic religious group which sprang up in the 12th Century in Southwestern France, the richest and most cultured provinces in Europe at the time. They began as a heresy but soon evolved into an essentially non-Christian movement. Their basic belief was Manichean, that is in the absolute duality of good and evil, and that Jesus had not actually been present on earth in the flesh.

They gained considerable support among the educated and noble classes, including that of Count Raymond VI of Toulouse, one of the most powerful lords in all Europe at the time, but it is unclear the extent to which the common people took to Albigensianism. The Church initially attempted to deal with them using its traditional methods, flooding the region with monks preaching the orthodox line, a measure which met with some success. However, some of the Albigensian "elect" objected to this, and responded violently. The deaths of a Cistercian monk and other clergy caused Pope Innocent III to proclaim a crusade in 1208.

The resulting struggle was long and bloody (1208-1229), and the flourishing culture of the Langue d'Oc was destroyed along with the Albingensians.