This volume commemorates the three-hundred-fiftieth anniversary of the birth of the Icelandic scholar and antiquarian Arni Magnusson, who served as secretary of the Royal Archives and professor of Danish antiquities at the University of Copenhagen, in addition to building the most important collection of early Scandinavian manuscripts in existence. The book presents descriptions of sixty-six manuscripts from the collection, one for each year of Magnusson's life, complemented by high-quality color photographs, a comprehensive introduction to Magnusson's life, and a chapter on book production in the medieval period. Published in collaboration with the Arnamagnaean Institute at the Department of Nordic Research, Copenhagen and the Arni Magnusson Institute for Icelandic Studies, Reykjavik.