In Europe, Cathari were a sect at odds with the Catholic Church during the 11th to 13th centuries. They believed in 2 gods, the evil Creator God Rex Mundi and Jesus. Like Marcionites in the 2nd and 3rd centuries, Cathari in the Middle Ages were dualistic. It is unclear whether Catharism was a continuation of Marcionite thinking.
Source: tatoeba (10726712)