Corneille starts to studie art in Amsterdam in 1940 and attends studies from time to time here he among others meets Appel.
During the war he gets fascinated by Matisse and Picasso, but after the war he is more impressed by The French School, among others Pignon. Corneille had his first exhibition in 1946, he spent som months in Hungary, in Budapest he visited a library and "discovered" the surrealism, and at the same time he got some inspiration from Miro and Klee.
In 1948 Corneille, Appel, Constant and others start the 'Experimentale Group' and the magazine 'Reflex' this group later becomes an important part of Cobra.