1909-1912 School of Applied Arts, Stuttgart. 1913-1914 Applied Arts School, Dresden. 1920-1923 master atelier. 1924 studies printmaking under Ernst Ludwig Kirchner in Davos. 1929 moves to Hamburg. Member of the 'Hamburg Secession'. 1933 moves to Oslo. Visits Edvard Munch. 1936-1937 visits from Kurt Schwitters and Ernst Wilhelm Nay. 1946 becomes a Norwegian citizen. 1950 travels to New York. 1951 moves to Aal in Hallingdal (Norway). 1962 'Venice Biennale'. 1972-1973 retrospective of his material pictures, graphics, and sculptures in Oslo.