I could never have undertaken this book if Picasso had not honored me with his friendship from the end of 1945 until his death. He gave me free access to his personal collection, particularly after it was installed at the mas of Notre-Dame-de-Vie at Mougins. What he gave me far exceeds the generous clarifications and explanations he readily produced for me, and the close attention with which he followed my work on the catalogues raisonnés. The cumulative experience for me was one of unforgettable human richness, with which I also associate Jacqueline. It would not have been the same without her.
Subsequently, I was able to complete my personal knowledge of Picasso's work by participating in the commission which chose from his estate the works kept by the French nation in payment of death duties. I owe a great deal to my collaboration with the original organization of the Musée Picasso in Paris, to Michèle Richet, Dominique Bozo, Hélène Seckel, Marie-Laure Bernadac, Laurence Marcillac. And, because he allowed me to share his research for the Museum of Modern Art exhibitions "The Late Cézanne," "Pablo Picasso: a Retrospective," and "Primitivism and Twentieth-Century Art," William Rubin has provided unparalleled stimulation.
Among the exhibitions in which I participated, "Der Junge Picasso" at the Kunstmuseum in Berne with the late Jürgen Glaesemer, "Picasso 1905‐ 1906" at the museums of Barcelona and Berne with Maria-Teresa Ocaña and Jean-Christophe Von Tavel, and "Picassos Klassizismus" and "Picassos Surrealismus" at Bielefeld with Ulrich Weisner provided opportunities for fruitful review. But my work with William Rubin, Hélène Seckel, and Judith Cousins on the Demoiselles d'Avignon exhibition of 1988 at the Musée Picasso in Paris and my participation in organizing "Picasso and Braque: Pioneering Cubism" at the Museum of Modern Art in New York are among the principal sources for this edition as opposed to the original French edition of 1987. Together with Judith Cousins, William Rubin, and the late Edward Fry, to whom I wish to give particular recognition, and with the acquisition of fresh information, I participated in the complete revision of the previously accepted chronology for the years 1905-1914.