The Koetser family of art dealers began with Henry Koetser and his wife, Bertha van Ameringen, who opened their gallery in Amsterdam after World War I. In 1923 they moved to London with their sons Max, Leonard, and David M. Koetser. The three brothers set up their own art dealing business there. David M. Koetser and his wife Betty moved to New York in 1939, setting up their own gallery, while Leonard remained active in London. The brothers officially split up their businesses in 1948. In the mid 1960s, David M. and Betty 'retired' to Switzerland, although once there they again established a gallery, on the Talstrasse. The David M. and Betty Koetser Foundation made a major gift of paintings to the Kunsthaus Zurich in 1987; David M. died in 1992. His nephew, Leonard's son David H. Koetser, had meanwhile entered the family business in London and opened a gallery in Geneva. In the early 1980s, Leonard and David H. consolidated the Koetser art dealings at the Talstrasse gallery in Zurich, where it remains active to this day.