In a career spanning over six decades, the New York art dealer Pierre Matisse (1900--1989) contributed substantially to the advancement of modern art. At his eponymous gallery on East Fifty-seventh Street, he showed several now legendary artists for the first time outside Europe. The collection--paintings, sculpture, and drawings by Balthus, Bonnard, Chagall, Derain, Dubuffet, Giacometti, Magritte, Miro, and the dealer's own father, Henri Matisse, among others--was donated to The Metropolitan Museum of Art in 2004 by the foundation established by his widow. These extraordinary artworks are presented with informative entries addressing the circumstances of each work's creation and the dealer's relationship to the artist. In the introduction, the story of Pierre Matisse's early struggles in New York is told for the first time and illustrated with previously unpublished archival photographs.