Founded in the 16C by Julius, Duke of Brunswick-Lüneburg, in the 17C the library was the largest in all German-speaking territory. Still widely used by scholars for research, it houses a million volumes, including priceless medieval illuminated manuscripts (Henry the Lion's 12C gospel book). Globes, maps and a portolan (nautical chart) provide insights into geographical knowledge in the 15C, 16C and 17C.