Max Ernst was an avant-garde artist who helped found the Dadaist and Surrealist movements and organize exhibitions of the works. He was arrested during the Nazi occupation of France in World War II but was released through the intervention of art collector Peggy Guggenheim, whom he later married. Along with other artists and friends who were fleeing the war, he went to the USA in 1942 and helped introduce new art forms to Americans. In 1948, he wrote the treatise Beyond Painting, which helped bring him publicity and financial success. In the late 1950s, Max Ernst returned to live in France with his second wife, Dorothea Tanning. The Galeries Nationales du Grand-Palais in Paris published a complete catalogue of his works.