The publication of the first two volumes of a catalogue that will eventually encompass the entire collection of The Solomon R. Guggenheim Museum affords a welcome opportunity to summarize, in broad outline, this institution's now almost forty-year history. For it is obvious that the accumulation of paintings and other works of art is the result of a systematic effort that has involved, through the past decades, Presidents, Boards of Trustees, Directors, and Staff. The Collection now in our custody, and subject to further envelopment, may therefore be regarded as the Guggenheim's most tangible monument as well as its greatest asset. From our present vantage point, the history of the Solomon R. Guggenheim Foundation, the parent body of the Museum itself, falls into three clearly separable phases. The first of these 1937 to 1949 begins with the creation, by my grandfather, Solomon R. Guggenheim, of the Foundation that bears his name, and ends with his death. It coincides approximately with the lifetime of the Museum of Non-Objective Painting and the term of its first Curator and Director, the late Baroness Hilla Rebay von Ehrenwiesen.