Karli Sohn-Rethel (actually Carl Ernst Sohn-Rethel), a descendant of the famous late-romanticist Alfred Rethel and brother of Otto and Alfred Sohn-Rethel, is regarded an important representative of German Modernism.
After attending academies in Düsseldorf and Dresden, where he was taught by the plein-air painter Carl Bantzer, who was also the teacher of Kurt Schwitters, Karli Sohn-Rethel would soon come into contact with the avant-garde: As of 1911 he was a member of the "Sonderbund", in 1919 he took part in the legendary opening exhibition of the Galerie Alfred Flechtheim, additionally, he showed works in exhibitions of the "Jungen Rheinland" [Young Rhineland] and the Rheinischen Sezession [Rhenish Secession]. Journeys to Italy, Bali, India and Africa had decisive impact on the paintings and graphic works of Karli Sohn-Rethel, his style followed that of Paul Cézanne.
The oeuvre of Karli Sohn-Rethel was largely destroyed in World War II. Some of his works are in possession of the Suermondt-Ludwig-Museum in Aachen and the Wallraf-Richartz-Museum in Cologne.