Provenance Research and the related search for cultural objects appropriated during the National Socialist persecution applies to the majority of post-1933 purchases for all collections of the Staatliche Museen zu Berlin (National Museums in Berlin). The aim is to verify, wherever possible, the complete provenance of purchased art works formerly in Jewish ownership and hence to contribute to the clarification of ownership rights. In order to achieve this, documents, collection inventories and object documentations within the respective museums are evaluated for evidence, as is the archive material kept in the Zentralarchiv (Central Archive) of the Staatliche Museen zu Berlin. The most substantial, content-rich records of the National Gallery have already been indexed systematically and thoroughly, taking into account the numerous transactions documented (purchases and lending transactions, offers, requests etc.). The data collected in the process is fed into a database. It includes the name of the artist, title of the work, name of the vendor or supplier, file number and document number, as well as further references and comments. The electronic database serves as a research instrument which assists in the search for information; it is used by the museums for their own provenance research and is also available as a data source to researchers from other institutions.
Further, it seemed advisable to extend the documentation: not to restrict research to the provenance of the museums' art works formerly in Jewish possession, but to record all those artists and art works which are mentioned in the files in the context of an offer for loan or sale, irrespective of whether an actual purchase was made. The evaluation of records on purchases, offers and loans will provide a wealth of data for provenance research, especially since the museums received numerous offers to buy from the art trade as well as private individuals. This information will offer insight into many a link to private and public collections and to former owners - traceable provenances are thus created.