The foundations of the “Modern Gallery and Graphic Art Collection – Rupertinum,” the precursor institution of today’s Museum der Moderne Salzburg, were laid in 1976 when the Salzburg art dealer Friedrich Welz donated his collection to the province of Salzburg. From the late 1990s onwards, it became increasingly clear that he had played a questionable role in the Austrian art business during the Nazi era, when the process of so-called “Aryanization” enabled some to enrich themselves at the cost of others. The Museum reacted by setting up its own office for provenance research in 2004. The origins of the works in the “Welz Donation” were investigated scrupulously, as were the origins of all the works in the collection that had been painted before 1945, and its holdings of graphic art up to 1945. This provenance research examined a total of 650 paintings and approximately 1,400 prints. The results of this extensive research were published in the catalogs Vom Tafelbild zum Wandobjekt. Zum Sammlungsbestand des Museum der Moderne Salzburg (2 vols., 2005 and 2006) and Im Blätterrausch. Zeichnungen, Aquarelle, Collagen bis 1945 (2010).
In 2011, one of the most famous, valuable paintings in the collection of the Museum der Moderne Salzburg – Litzlberg am Attersee (ca. 1915) by Gustav Klimt (1862–1918) – was returned to its rightful owner, Georges Jorisch, the heir of Amalie Redlich (née Zuckerkandl). In gratitude for this restitution, Jorisch provided generous financial means for the reconstruction of today’s Amalie Redlich Tower on the Mönchsberg.
In the course of the provenance research project, it transpired that the pastel Jeanne Pontillon à la capeline (1884) by Berthe Morisot (1841–1895) was also of questionable provenance. As a result, the provincial government of Salzburg decided to return it to the heirs of the collector David David-Weill (1871–1952). After a lengthy process of tracing them, the work was able to be returned in 2016.