This two-volume catalogue documents the collection of Helga and Walther Lauffs, one of Europe's most important private collections of twentieth century post-war art, comprising key examples of Pop Art, Arte Povera, Minimalism, Post-Minimalism, and Conceptual Art. The Lauffs built their collection over the course of the late 1960s through the 1970s with the guidance of curator and art historian Paul Wember, who was known for the visionary program of contemporary art that he developed as the director of the Kaiser Wilhelm Museum in Krefeld between 1947 and 1975. In its vision and scope, which is made evident by the rigorous and broad selection of the art of their times, they succeeded in building a collection that bridges the gap between European and American artistic sensibilities. Their collection provides a singularly focused overview of art produced around the 1960s and 1970s, offering connections among its diverse artworks, while pointing forward to the work of successive generations of artists. In two fully-illustrated volumes, the catalogue incorporates over 100 color plates, with newly-commissioned scholarship and extensive research and documentation on the works in the collection, including important works by Joseph Beuys, Mel Bochner, Lee Bontecou, Christo, Joseph Cornell, Hanne Darboven, Jan Dibbets, Lucio Fontana, Eva Hesse, Donald Judd, On Kawara, Yves Klein, Joseph Kosuth, Sol LeWitt, Piero Manzoni, John McCracken, Mario Merz, Robert Morris, Bruce Nauman, Louise Nevelson, Claes Oldenburg, Giulio Paolini, Michelangelo Pistoletto, Fred Sandback, George Segal, Richard Serra, Richard Tuttle, Cy Twombly, Günther Uecker, Tom Wesselmann, and Douglas Wheeler, among other key artists of the twentieth century.