It doesn´t happen often, but the results are often fascinating when it occurs. The art collector Jacques Doucet (1853–1929) had an extraordinary collection of books, sculpture, paintings and furniture from the eighteenth century. This changed at the end of the nineteenth century and beginning of the twentieth century however. He had inherited from his family and earned himself a fortune as successful fashion designer and was in touch with the avant garde of cubism, (Neo- and Post-) impressionism and expressionism. In 1912, he sold his collection of art from the eighteenth century to finance his new collection of works by Picasso, De Chirico, Derain, Brancusi, Duchamp, Van Gogh, Max Ernst, Klee, Degas, Sisly, Monet and Cézanne. His most original contribution was his hôtel particulier however, 33 rue Saint-James, Neuilly-sur-Seine (Paris). This house was designed by famous cubist and art-deco architects, sculptors and painters and is open to the public nowadays. The hôtel is one of the hidden treasures of Paris and the Interbellum.