This is the first comprehensive source-based account of the fate that befell the books in the largest German library after 1939. During the war, nearly all the books and manuscripts were evacuated from Berlin. Later, parts of the stock were plundered and damaged. Significant stocks are today located in Poland and Russia. The new findings, some of them quite surprising, are registered and illustrated in an appendix with extracts from the sources, illustrations, evacuation tables, an index and a coloured outline map.