Paul Cassirer and his cousin, Bruno Cassirer, founded their firm in Berlin in the late 19th century. Paul Cassirer separated from his cousin in 1903, and in the years before the first World War handled 19th century French masterpieces in his gallery, among them many paintings by Cezanne and Van Gogh. He committed suicide in 1926, after having rebuilt the art firm and publishing house after the war. The firm was then taken over by Dr. Grete Ring and Dr. Walter Feilchenfeldt, and remained under their leadership until 1933. At that time Feilchenfeldt, his wife Marianne, and their son emigrated from Nazi Germany, first to Holland, then England, and eventually to Switzerland in 1939. Feilchenfeldt established his firm Zurich in 1948; after his death in 1953 it was directed by his widow, Marianne Feilchenfeldt, and their son Walter.
25 Jahre. Feilchenfeldt in Zürich. Zürich, 1973 (introduction by Marianne Feilchenfeldt).
Tafel, Verena. "Paul Cassirer als Vermittler Deutscher Impressionistischer Malerei in Berlin. Zum Stand der Forschung." Zeitschrift des Deutschen Vereins für Kunstwissenschaft 42 (1988): 31-46.