Display case in the intervention room provenance research 2022 with correspondence, publications and inventory lists.

The Kunsthaus Zürich has documented the origin of the works in its collection ever since the museum was established in 1910, and comprehensive results of this work were published for the first time in the 2007 collection catalogue. For two paintings by Albert von Keller, gifted from the estate of the Zurich art collector Oskar A. Müller in 2007, which were identified as Nazi-looted art, ‘just and fair solutions’ within the meaning of the Washington Principles were found, in 2009 and 2010 respectively.

Starting in 2017, with support from the Federal Office of Culture (FOC), this provenance research has been taken to a new level. In 2019, the Kunsthaus created a permanent provenance research position. Since then, the provenances of the collection holdings have undergone systematic research that is open in terms of results, in accordance with international standards, with the conclusions continually being published in the online collection. This includes, under the terms of the new subsidy agreement with the City of Zurich, a review of the works on long-term loan to the Kunsthaus. (*1)

Access to the archives and research enquiries

The Kunsthaus responds to all provenance-related enquiries with due care. The comprehensive and well-organized archival fonds of the Zürcher Kunstgesellschaft up to 1949 are publicly accessible to anyone interested in the Kunsthaus library. Part of this is already accessible online at digital.kunsthaus.ch. If it were to be shown that the Zürcher Kunstgesellschaft holds a work that was removed from a previous owner as part of the Nazi persecution between 1933 and 1945, efforts would be made to achieve a just and fair solution with that owner’s legal successors in accordance with the Washington Principles.

Contact: provenienzforschung@kunsthaus.ch

Principles in provenance research

The Kunsthaus Zürich conducts its provenance research in accordance with the International Council of Museums (ICOM) Code of Ethics for museums, along with the Washington Principles of 1998 and the follow-up Terezín Declaration of 2009. (*2) In the new subsidy agreement with the City of Zurich, the Zürcher Kunstgesellschaft has also committed to carrying out its provenance research in line with the concept of ‘cultural property confiscated as a result of Nazi persecution’. This may also include, following in-depth investigation and clarification of specific circumstances, artworks sold by emigrants in what are termed ‘safe’ third countries outside the area of Nazi rule, such as Switzerland. This development is taking place against the backdrop of a far-reaching social and political debate which is to be conducted nationwide and involve a diverse range of voices. Museums such as the Kunstmuseum Bern, Kunstmuseum Basel and Kunsthaus Zürich are contributing to this debate by updating their strategies for dealing with ‘cultural property confiscated as a result of Nazi persecution’.


The Presidium and management of the Zürcher Kunstgesellschaft welcome the creation of an independent expert commission for historically contaminated cultural heritage at national level as of 1 January 2024.

As a result of this decision at federal level, the Kunsthaus has decided not to set up its own international commission of experts, as previously announced.

December 2023

* Footnotes can be found in the strategy paper. Download PDF


Provenance research

The aim of provenance research is to investigate the ownership details of artworks since the time of their creation. The focus is on works which changed hands during the Nazi period and the persecution and murder of Jews as well as other minorities.

Cultural property confiscated as a result of Nazi persecution (Nazi-looted art)

The term ‘Nazi-looted art’ refers to cultural property which the Nazis confiscated from its mostly Jewish owners between 1933 and 1945. This took the form of seizures, forced sales, and other actions conducted under duress. It can also include sales of what have previously been referred to in Switzerland as ‘flight assets’, which took place outside the area of Nazi rule.

Washington Principles (1998) and Terezín Declaration (2009)

The Washington Principles form the basis for research into, and treatment of, Nazi-looted assets. They have been adopted as a legally non-binding declaration by 44 states, including Switzerland. Their primary aim is to identify Nazi-looted art. Where ownership is disputed, alternative solutions such as commissions should be set up and ‘just and fair solutions’ found between the heirs of the former owners on the one hand, and the current holders on the other.

The Terezín Declaration expanded the definition of looted art contained in the Washington Principles, setting out rules covering cultural property sold under duress owing to Nazi persecution.

Just and fair solutions

‘Just and fair solutions’ comprise a spectrum of different measures. These can include publicly acknowledging the circumstances of confiscation in an exhibition or mentioning the provenance history when the work is displayed in a museum. Payment of compensation is another option, as is the sale of the work to third parties, with the proceeds being shared, or subsequent loan to the current holders. The best-known solution is returning the work to its rightful owner (restitution).

Research projects

Acquisitions for the Collection 1946–1960 (2023–2024)

Acquisitions for the Collection of Paintings and Sculptures, 1946–1960 (2023–2024)

The project "The Acquisitions for the Collection of Paintings and Sculptures 1946-1960 (2023-2024)", cofunded by the Federal Office of Culture, will systematically investigate the changes of ownership during the Nazi period between 1933 and 1945 of the post-war acquisitions between 1946 and 1960 of the Collection of Paintings and Sculptures of the Kunsthaus Zürich. In a first step, the project involves examining the existing provenance details of 248 works. In a second step, around 80 works will be examined and documented on the original and the provenances of these works will be checked, supplemented and researched.

The results can be seen in our list of works (in German) and will be progressively published in the Online Collection.

The Donations Ruzicka/Bär/Haefner (2021–2023)

The Provenances of the Donations Leopold Ruzicka (1949), Nelly Bär (1968) & Walter Haefner (1973–1995) (2021–2023)

Supported by the Federal Office of Culture, the project entitled ‘The provenances of the gifts by Leopold Ruzicka (1949), Nelly Bär (1968) & Walter Haefner (1973–1995)’ investigates the changes of ownership of the three central post-war gifts during the Nazi period from 1933 to

1945. It examines the 74 original, pre-1945 paintings, sculptures and drawings from the three gifts, documents them and reviews the art-historical corpus, as well as verifying, researching and supplementing their provenances. The project covers the 47 works that now make up the Old Master collection of Leopold Ruzicka, as well as the two prestigious gifts of French modernist works made by Nelly Bär and Walter Haefner, comprising 28 and 14 items respectively. These will constitute the first examples of systematic research, documentation and publication relating to the extensive and pivotal accessions from private lenders and donors.

The results will be progressively published in the Online Collection.

Download final report (German)

Letterpress copybooks of the ZKG / KHZ 1933–1945 (2021–2022)

Research project: letterpress copybooks of the ZKG / KHZ 1933–1945

Wilhelm Wartmann (1882–1970), the first Director of the Kunsthaus Zürich, served in that role from 1909 to 1949. The extensive administrative files from his period in office have been preserved almost in their entirety. Thanks to their alphabetical registers of addressees, the letterpress copybooks containing all outgoing communications from the Kunsthaus are an excellent tool for accessing the entire archive and enable all items of business to be found relatively easily. The 63 volumes covering the years 1933 to 1945 that are being published here for the first time include details of exhibitions, purchases, loans of artworks, items deposited, sales, imports and exports, and much more besides – information that is not available anywhere else.

The letterpress copybooks are divided into two series: ‘Exhibition’ and ‘General Correspondence’. Within each, the letters are filed chronologically, making it easy to browse through a given period. The registers of addressees have been transcribed, so that it is possible to search by names of persons and entities. However, the historical register entries are not always complete.

The volumes are being published progressively, starting with ‘Exhibition’, as part of a project supported by the Federal Office of Culture.

Letterpress copybooks online

Download final report (German)

Collection of Prints and Drawings 1933–1950 (2017–2019)

Collection of Prints and Drawings research project 1933–1950 (2017–2019)

Supported by a grant from the Federal Office of Culture, this project aimed to research and make public the provenances of all new acquisitions made by the Collection of Prints and Drawings from 1933 to 1950. During this period, some 10,000 works on paper were donated to or acquired by the Collection. The research project focused on some 3,900 items.

None of the works showed clear evidence of having changed hands due to confiscation and therefore being Nazi-looted art. Approximately two thirds of the provenances can be classified as unproblematic and complete, or as incomplete but without any indication of questionable changes of ownership. In the remaining cases the previous owner at least was successfully identified, but there is a need for further research.

The results can be seen in our list of works (in German) and will be progressively published in the online collection.

Download final report (in German)

List of works artists A–L
List of works artists M–Z

Online collection for provenance (2017–2018)

Online publication of the provenance of works in the Collection of Paintings and Sculptures (2017–2018)

The provenance of works in the Collection of Paintings and Sculptures were reviewed when the main catalogue of paintings and sculptures was being compiled between 2002 and 2007, with a particular focus on the works donated to the Kunsthaus since the 1950s. The documented provenances of the works have been published in the main catalogue and online . They are also being progressively added to the online collection, which has been developed with support from the Federal Office of Culture.

Download final report (in German)

All research projects supported by:

Albert Keller, Adele von Le-Suire, stehend, about 1887, Kunsthaus Zürich, in 1939 deprived from Alfred Sommerguth by the Nazis, donated by his heirs and Hannelore Müller in 2010

A just and fair solution

Agreement with the heirs of Alfred Sommerguth & Jean and Ida Baer

In 2009, the Kunsthaus staged an exhibition on the work of Albert von Keller to mark a major gift of his paintings from the estate of the Zurich art collector Oskar A. Müller in 2007. On the basis of the catalogue compiled for the exhibition, external experts established that one of the paintings in the gift, ‘Madame la Suire’, could be looted art. Once owned by the Jewish art collector Alfred Sommerguth, the work turned out to have been compulsorily auctioned by the Nazi authorities in Berlin a few months before the outbreak of the Second World War. The Kunsthaus reviewed the evidence and, when the suspicions were confirmed, offered to return the work to the original owners’ heirs or purchase it from them. However, the heirs generously decided to donate the oil painting to the Kunsthaus, merely requesting that a notice to this effect be placed by the work when it is exhibited.

Alfred von Keller’s ‘Nude on a Beach / Evening’, which was stolen from the collection of Jean and Ida Baer by the Nazis in 1940, was also affected. In 2012, following an agreement involving the heirs and the gift of Hannelore Müller, it was acquired by the Kunsthaus.


Provenance categories

The Kunsthaus Zürich classifies the provenance of its works based on the provenance categories developed by the Kunstmuseum Bern ('Berner Ampel', 2021). The categories 'yellow-green' and 'yellow-red' are dynamic and allow a qualitative assessment for works with incomplete provenance. The former stands for 'no evidence of Nazi looted art' and the latter for 'evidence of Nazi looted art'. This distinction makes it possible to do justice to the dynamic findings of research and to reflect them adequately. Moreover, a categorisation as 'yellow-red' can also be the basis for a fair and equitable solution in accordance with the Washington Principles (1998).

In addition to public publication on the online collection, the categorisation is also used in the collection rooms. Works whose provenance is being researched are marked there.