The story
During World War II, the cultural artifacts and fine arts in Prussia, especially in Berlin, came under increasing threat of loss. To protect them from Allied bombing, millions of items were evacuated to relative safety in monasteries, castles and abandoned mines around Germany starting in 1941. With the collapse of the Third Reich in 1945, many of these collections wound up damaged, destroyed, or variously hidden in the Allied occupation zones. All the former Prussian institutions ceased to officially exist when the State of Prussia was abolished in 1947, placing these assets in further doubt. As Germany became divided into West and East, what remained of the buildings and scattered collections were also separated by the Iron Curtain.
The Prussian Cultural Heritage Foundation began in 1957 by a West German constitutional mandate to find and preserve the collections still stored throughout the former western occupation zones. In 1961, efforts began to move these materials to West Berlin. From the mid-1960s onward, a series of Modernist buildings were constructed at the Kulturforum to serve as new homes for the collections, including the Gemäldegalerie, the Neue Nationalgalerie and the Berlin State Library. Upon German Reunification in 1990, the Foundation's role expanded considerably to encompass many of the most important cultural properties of the former East Germany. The most important tasks today are in the consolidation of collections, reconstruction of physical space, conservation-restoration and Provenance research.
From Wikipedia’s article on Prussian Cultural Heritage Foundation, shared under CC BY-SA 4.0.4