The Berlin State Library was founded in 1661 by Frederick William of Brandenburg, as 'Library of the Prince‐elector'. In 1701, the library was renamed 'Royal Library at Berlin'. It kept this name until the end of monarchy in Germany in 1918, at which time it was renamed as the 'Prussian State Library'. During World War II, the entire holdings (at the time some three million books and other materials) were hidden to safety; in 30 monasteries, castles and disused mines. A part of its collection was returned to the original Berlin site at Unter den Linden (East) after 1945, and some relocated items were initially brought to West Germany, and stored after the late 1970s in the new building in Potsdamer Straße in Berlin (West). Some items of the collection are still located in Poland and the territories of the former Soviet Union.
Staatsbibliothek zu Berlin, Potsdamer Straße 33, 10785 Berlin, Germany, Google Maps