Marcel Duchamp's disguises and countless photographic self-portrayals, and his humorous commentaries on art, the art industry, art criticism, and art history, are legendary in word and image. Less well known is a Marcel Duchamp who, with great empathy and strategic awareness, embraced the cause of the artists in his contemporary cultural environment: as curator of exhibitions from the early 1910s to his death in 1968, as juror and consultant for some of the most important collections, museums, and galleries of modern art. The volume outlines nearly seventy exhibitions, supplemented by recent research findings, and illustrates Duchamp's close cooperation with leading figures of his time, including Louise and Walter Conrad Arensberg, Katherine S. Dreier, Francis Picabia, Sidney and Harriet Janis as well as Andre´ Breton, Julien Levy, and Peggy Guggenheim.