The Cathar or Albigensian heresy was centred in southern France, mainly in the eastern areas of the Languedoc, between about 1000 and 1350. They believed that the world and everything in it was intrinsically evil. They believed that Christ was a ghost, nothing more. They also had some very weird, by Christian standards, views on religious observance (none) and the Church (fat and corrupt). What followed was a foregone conclusion, really.

The crusade and subsequent inquisition which put the heresy down was probably one of the worst that there has ever been, because it was essentially a civil war with one side convinced that no matter what happened they would triumph through spirituality, and the other basking in the warm approval of the Catholic Church as they butchered and burned, maimed, tortured and plundered. The real surprise is just how long it took the Church and the French between them to put it down.

The Languedoc was virtually depopulated in the process. Nearly everyone living there was either an Albigensian or a sympathiser according to the Church, which acted appropriately and obligingly killed most of them.

All jolly good fun!