Begun during the reign of Friedrich Wilhelm, the Great Elector, who acquired 2,500 drawings and watercolours in 1652, the library now enjoys an international reputation. It possesses some 110,000 drawings and watercolours from the 14C-20C and nearly 550,000 engravings from the late Middle Ages to the present day. The collection of drawings by old German and Dutch Masters - including 80 by Rembrandt - is unique in the world.