The Catalogue of Books Printed in the 15th Century in Swedish Collections is the first major Swedish contribution to international incunabula research since the middle of the 20th century. Wolfgang Undorf revitalizes the seminal contributions by 19th century Swedish scholars to the field of the history of early printed books. It is a catalogue of a wide range of products of printing presses from all over Europe during the second half of the 15th century. It is based on a national incunabula census, carried out by the author between 2003 and 2006 to commemorate the hundredth anniversary of the first printed Swedish incunabula catalogue in 1904. The author has completed, updated and enriched the catalogues of incunabula collections in Swedish libraries published by his predecessors Collijn and Sallander with more than 2000 new entries as well as with comprehensive indexes. This first national Swedish incunabula catalogue ever reveals a quantitatively and qualitatively higher commitment to incunabula in Sweden than generally assumed. It also proves that incunabula were and still are widely spread over a wide range of cultural institutions, revealing an impressive historical commitment to literary culture and book collecting all over the country. This comes to light in the provenance index that contains more than 2,000 names and locations, among others one of the largest lists of contemporary book owners from Scandinavia. Thus Undorf's catalogue is a significant and lasting contribution to the history of the early printed book in Sweden, Scandinavia and Europe.