Skull of the German philosopher and mathematician Gottfried Wilhelm Leibniz (1646-1716). Photograph taken by "Georg Alpers junior" in 1900 to 1906 when the grave in Hannover was opened. Provenance: The estate of Ernst August von Hannover, 3rd Duke of Cumberland. The photograph an a second one with a side view had been offered in 2011 by "Galerie Bassenge" in Berlin for 900,-- Euro ...