After the Second World War, anybody who had lost works to the enemy, or had information on artworks that got into enemy hands, was obligated to inform the Netherlands Art Property Foundation (Dutch: Stichting Nederlands Kunstbezit or SNK) by way of a declaration form. Nowadays, these declaration forms are still being kept in the archive of the Netherlands Art Property Foundation.

The Netherlands Art Property Foundation was founded by the Dutch government to recuperate and restitute works of art, and used the thusly gathered information to trace and retrieve works of art in Germany. This led to the recuperation of many art objects. A part of these objects could not be traced by the Netherlands Art Property Foundation and remained in this sense 'missing'.

From 2015 onwards, the Origins Unknown Angency executed a two-year project in which information on the objects that were never retrieved by the Netherlands Art Property Foundation has been digitized. Approximately 15.000 Declaration Forms have been scanned, and information from these forms has been largely entered into a database. The project was made possible by support of the National Archive and was financed by the Ministry of Culture, Education and Science and the American organisation Conference on Jewish Material Clainms Against Germany.

A part of the digitized data can be consulted on this website.

When consulting this site, some points of attention need to be taken into account:

• An important part of the total amount of Declaration Forms has not been publicized on this website. If an object cannot be found on this site, this does not mean that there is no information available on the object. It also does not mean that an object has not been lost involuntarily as a result of the Nazi-regime. If you are looking for information on a specific work of art, and you cannot find information about this object on the site, it is recommended to look at the new portal of NK Collection or contact the Cultural Heritage Agency via restitutie@cultureelerfgoed.nl
   
• The information on the Declaration Forms from the archive of the Netherlands Art Property Foundation have been transcribed with the best of effort and have been interpreted where neccessary. In some cases, additional research has been conducted. The results of such research have been recorded with a reference to the consulted sources.
   
• The meaning of the terms confiscation, theft, forced or voluntary sale, as indicated on the Declaration Forms, may not always be in accordance to the current understanding or contemporary notions.
   
• Because of the amount of the material, it was not possible to systematically verify if there had been restoration of rights after the war. References to whereabouts of works of art after 1945 have been made to the best of knowledge. It is, however, not guaranteed that these works are to be identified as the works mentioned in the Declaration Forms.
   
• If an object is mentioned on this website, that in itsself does not mean that the work has been lost as a result of looting, forced sale, confiscation, or that the work has been lost involuntarily in any other way.
   
• The information on this website is not conclusive or complete. Because a lot of archival material has been lost, the fact that a work of art of certain provenance information is missing should not lead to the conclusion that the possession has not been lost as a result of plunder, confiscation, forced sale or any other form of involuntary loss.
   
• It cannot be guaranteed that the works of art are attributed to the proper artist. The spelling of provenance names my vary.

For information about a specific work of art or for other questions, you may direct a request for information by e-mail at the Cultural Heritage Agency via restitutie@cultureelerfgoed.nl