American avant-garde writer, patron, and collector of art. Together with her brother Leo, the Steins created a an important collection of works by Henri Manguin, Pierre Bonnard, George Braque, Pablo Picasso, Paul Cézanne, Pierre-Auguste Renoir, Honoré Daumier, Henri Matisse, and Henri de Toulouse-Lautrec. This collection was later split between the two of them. The salon frequented by artists and writers at the Stein residence at 27 rue de Fleurus in Paris is thought to have helped define Modernism in the early 20th century. Gertrude lived with her companion Alice B.