Dutch painter, architect, designer and writer. He was officially registered as the son of Wilhelm Kepper and Henrietta Catharina Margadant, but he was so convinced that his mother second husband, Theodorus Doesburg, was his father that he took his name. Little is known of his early life, but he began painting naturalistic subjects c. 1899. In 1903 he began his military service, and around the same time he met his first wife, Agnita Feis, a Theosophist and poet. Between about 1908 and 1910, much influenced by the work of Honor Daumier, he produced caricatures, some of which were later published in his first book De maskers af! (1916). Also during this period he painted some Impressionist-inspired landscapes and portraits in the manner of George Hendrik Breitner. Between 1914 and 1915 the influence of Kandinsky became clear in such drawings as Streetmusic I and Streetmusic II (The Hague, Rijksdienst Beeld. Kst) and other abstract works.