A $300 Million Art Trove and the Labyrinth of Nazi-Era Art Claims

A new chapter has opened in a bitter 17-year battle for the Guelph Treasure, one of the most valuable art troves claimed by the heirs of Jewish victims of Nazi rule, after the discovery of documents in a German archive indicating that its sale in 1935 was made under duress.

The trove, estimated to be worth $300 million, consists of gem-encrusted medieval ecclesiastical artifacts, primarily reliquaries and crosses. The most valuable of these is a 12th-century reliquary shaped like a church and made of gold, silver and copper; it is adorned with figurines of biblical characters carved out of walrus tusk.

The dispute dates back to 2008, when the heirs of four art dealers who were members of a consortium of Jewish owners of the Guelph Treasure filed a claim with the current holder, the Prussian Cultural Heritage Foundation in Berlin. Since then, the case has grown ever more complicated, in part because the composition of the consortium cannot be fully reconstructed, despite much research.

And now, there is a new claim, by the heir of a consortium member, Alice Koch, whose interests had not been considered before. The claim comes as Germany considers a major change in settling restitution disputes. The government has announced it will dismantle its advisory commission on Nazi-looted art and replace it with a binding arbitration tribunal, but the timing of this switch is not yet clear.

Today, the Guelph pieces are prize exhibits at the Museum of Applied Art in Berlin, which is overseen by the Prussian Cultural Heritage Foundation. Earlier this month the foundation agreed to hold a new hearing with the German government’s advisory commission on Nazi-looted art because of the fresh evidence that the documents revealed.

Lawyers representing the Koch heir, whose great-grandmother owned 25 percent of the Guelph Treasure, discovered the German archival documents, which show that Koch was forced to pay the punitive “Reich flight tax” in October 1935 before fleeing to Switzerland. She used her proceeds from the sale of the Guelph Treasure, which took place four months earlier, to pay the Nazi regime’s bill for 1.2 million Reichsmarks, said Jörg Rosbach, the Berlin lawyer representing one of Koch’s heirs. The sum is equivalent to millions of dollars today.

“This was a discriminatory tax used against Jews,” Rosbach said. “One of the important questions in determining whether a sale was under duress is whether the seller was able to dispose of the revenue freely. Alice Koch was not.”

In 2014, the German advisory panel rejected the claim by the heirs of four dealers who were part of the consortium — a claim in which Koch’s heirs had no part. In a statement explaining its reasoning, the commission said that while it was “aware of the difficult fate of the art dealers and of their persecution during the Nazi period,” there was no indication “that points to the art dealers and their business partners having been pressured during the negotiations.”

The heirs of the four dealers — Isaak Rosenbaum, Saemy Rosenberg, Julius Falk Goldschmidt and Zacharias Max Hackenbroch — then pursued their claim in a U.S. lawsuit, right up to the Supreme Court. Those legal proceedings ended in July 2023 after the Court of Appeals for the District of Columbia confirmed a previous decision that U.S. courts lacked jurisdiction over the case.

The consortium bought the collection in 1929 with the intention of selling it for profit. They sold some 40 items, primarily in the United States. The heirs’ claims concern the remaining 44, which were sold in 1935 to the state of Prussia, then governed by Hermann Göring, Adolf Hitler’s top lieutenant.

Rosbach contacted the foundation in 2022 with the new evidence supporting Koch’s claim. “We agreed that we would start talks as soon as the court proceedings on the Guelph Treasure in the U.S. came to an end,” Rosbach said.

By April of last year, negotiations still had not started, so he submitted a claim on behalf of Koch’s heir to the advisory commission, he said. Markus Stötzel, the lawyer representing the heirs of the four dealers, also filed a fresh claim with the German advisory commission around the same time.

But for the advisory panel on Nazi-looted art to consider a claim, both parties must consent. After accusations of “delaying tactics” by the heirs, and under pressure from the advisory commission and the German culture minister, the Prussian Cultural Heritage Foundation agreed to a commission hearing.

The discovery of the documents introduces “a new aspect that we have to take very seriously,” said Hermann Parzinger, the president of the Prussian Cultural Heritage Foundation.

“This is a very complex, very convoluted case, and it has to be conducted with due care,” Parzinger said. He said the delay in agreeing to a hearing was because the foundation was trying to identify all the potential claimants for the treasure.

“Despite comprehensive research by the Prussian Cultural Heritage Foundation, the original composition of the consortium that sold the Guelph Treasure in 1935 is not fully known,” the foundation said in a statement.

This tangled case may be among the last that the German advisory panel tackles. The German government and 16 states have announced plans to dismantle the commission and replace it with the arbitration tribunal whose decisions will be binding. The new tribunal will also permit claimants to have unilateral access to it, rather than the current requirement that the holder of an artwork must also consent.

The advisory commission’s requirement for consent from both parties has long frustrated heirs because, in some cases, the trustees of German museums have simply refused to refer a dispute to the panel.

But the arbitration tribunal has yet to take shape. Its introduction, planned for this year, is likely to be overseen by a new government led by Friedrich Merz of the Christian Democratic Union. (Negotiations with the Social Democratic Party, his preferred coalition partner, are still in the early phases, and it may be weeks before a new culture minister is named.)

Regardless of the new government’s composition, “I think the plan to introduce arbitration has reached the point of no return,” said Benjamin Lahusen, a law professor at the Europa-Universität Viadrina in Frankfurt an der Oder.

Until the tribunal starts work, however, the advisory commission remains the recourse for claimants.

Adding to the complexity of the case is a third group of claimants, the heirs of Hermann Netter and another of Koch’s heirs, who are represented by another law firm. Netter was a jeweler who owned 25 percent of the Guelph Treasure.

Those heirs’ lawyers have initiated talks with the Prussian Cultural Heritage Foundation but have not submitted a formal claim.