In 1958, the Islamic Museum in the Pergamon Museum on the Museumsinsel received back most of the artworks transferred to the Soviet Union from 1945 to 1946 as looted art. With the restoration of other important collection objects, it became possible to open all exhibition rooms to the public by 1967. Based on the Unification Treaty, the two museums were organizationally merged in 1992 under the name Museum of Islamic Art.