Catharism was a Christian quasi-dualist and pseudo-Gnostic movement in northern Italy and southern France between the 12th and 14th centuries.
St. Paul, by Valentin de Boulogne.
The Fall of the Rebel Angels by Hieronymus Bosch
Painting by Pedro Berruguete portraying the story of a disputation between Saint Dominic and the Cathars (Albigensians), in which the books of both were thrown on a fire and Dominic's books were miraculously preserved from the flames.
Cathars being expelled from Carcassonne in 1209.
Bogomilism or Bogumilism was a Christian neo-Gnostic or pseudo-Gnostic dualist sect founded in the First Bulgarian Empire by the priest Bogomil during the reign of Tsar Peter I in the 10th century. It
Catharism
…mostly by the trade routes, and spread from the First Bulgarian Empire to the Netherlands. The movement appears to have been greatly influenced by the Bogomils of the First Bulgarian Empire, and may have originated in the Byzantine Empire, namely through adherents of the Paulician movement in Armenia and eastern…
Nemanja's Council against Bogomilism, organized by Stefan Nemanja. Fresco from 1290
Bogomil cemetery in Chalkidona (near Thessaloniki), Greece
Tetraevangelia of Ivan Alexander