Josef "Sepp" Angerer (1899–1961) was a rug merchant and art dealer who acted as an agent for Hermann Göring's private art collection, immediately before and during the Second World War. Art that Angerer dealt with for Göring came from a variety of sources: looted, acquired using threats, bought on the open market, and appropriated from museums.
Angerer was director of Quantmeyer & Eicke, of Kronenstrasse 61, Berlin, importers of rugs, furniture and works of art. In art matters he was second only to Walter Hofer in importance to Göring. Angerer used his international contacts to find art for the Göring collection and arranged the sale of the modern works that Göring did not want, thus raising funds to buy the tapestries and old master works that Göring preferred. Although he had strong Nazi connections, Angerer held no official position within the Nazi state.
The Nazis regarded any art that did not fit with their ideas of what art should be as Degenerate art. Almost all modern art was regarded as "degenerate". It was banned under the regime, seized and placed in special storehouses, and the artists who produced it were subject to sanctions. In 1938, Göring removed 13 paintings from the store of seized "degenerate art" at Kopenickerstrasse. Among others, works of Paul Cézanne and Vincent van Gogh that he sold through Angerer. German-born Dutch national Franz Koenig bought Van Gogh's Portrait of Dr. Gachet (first version, 1890) and Daubigny's Garden (1890), and Cézanne's The Quarry (c. 1900). Koenig died in 1941 when he fell under a train at Cologne station. According to Ivan Lindsay, Koenig was killed by the Nazis, so his collection of old master drawings could be taken from him. Of the remaining paintings, one by Edward Munch and one by Paul Signac were sold by Angerer in Sweden and two further Munchs in London. Göring paid compensation to the Städel Museum for the Van Gogh and the Folkwang Museum for the Cézanne but at a fraction of the paintings true worth.