Prior to World War I questions arose regarding whether one of the double-square canvases was a forgery. After the war legitimate Van Gogh paintings were mixed up with forgeries in the inventory of German art dealer
Otto Wacker. Wacker was put on trial after successfully selling a forgery of Van Gogh's self-portrait. Upon testimony of the best Van Gogh experts Wacker was sentenced for his crime, but mystery surrounding the forgery remained. In 1929 Ludwig Justi, the director of the
Berlin National Gallery, was particularly interested in the version of ''Daubigny's Garden'' (F776) owned by Paris art dealer
Paul Rosenberg. French painter and collector
Emile Schuffenecker, who was known to have made copies of Van Gogh's work, had at one point possessed this ''Daubigny's Garden
. Knowing that there were rumors surrounding the authenticity of the painting, Justi discreetly inquired about its provenance, and received "a detailed and reassuring answer." In 1929, about 70 individuals established the Verein der Freunde der Nationalgalerie
(Society of Friends of the National Gallery) to purchase art to lend to the National Gallery on a long-term basis. Daubigny's Garden'' was one of their first purchases, for 240,000 reichsmarks. ==See also==