On a recent morning, visitors trickled into the Africa wing of the Humboldt Forum in Berlin, a massive museum that opened in 2021 in a neo-Baroque reconstruction of the city’s former Royal Palace. The setup was familiar: Artifacts were enclosed behind glass and mounted onto white walls — an “ethnological display” of priceless artworks from a far-off land.

But this exhibition was different. Dozens of Benin Bronzes, intricate sculptures and plaques in metal that date back as far as the 13th century, were on display in Berlin for what may be the last time. Since July 2021, the artifacts no longer belong to Germany. They are part of a trove the country has begun to repatriate to Nigeria, beginning in December with the return of 20 bronzes. The exhibition tells not just the story of the objects, but also of their theft in 1897, when British forces sacked Benin City, looting the royal palace of the Kingdom of Benin in what is now southwest Nigeria.

Diagrams explain how the bronzes were acquired from European traders, while photos show British soldiers striking triumphant poses atop piles of loot. In one room, I joined tourists who watched videos depicting scholars, artists, German and Nigerian curators, and representatives of the royal family in Benin City discussing the significance of restitution.

The bronzes have been at the center of an international firestorm as calls mount for Western museums to take responsibility for how they obtained objects that were seized during the colonial era, or looted by Nazis and other invading forces.

For museumgoers, the ethical dimensions of viewing plundered art have become impossible to ignore. Western museums are major tourist attractions, drawing travelers from around the world. But what responsibility do we bear as spectators for patronizing institutions that display what critics say are stolen works? Should we be asking how these museums got their treasures? Does our conception of a modern-day ethnological museum need a dramatic rethink?

“There has been a great change of consciousness in the last years,” said Gilbert Lupfer of the German Lost Art Foundation, the world’s most extensive database for the search for Nazi-looted art. “More and more, visitors of museums have become interested in questions of provenance.” And most of them, he said, realize that works with a problematic provenance “can’t remain in the museum.”

A shift in perception, an increase in scrutiny

European and American museums have long resisted calls for repatriation, arguing that objects from Africa, Asia and elsewhere were legally obtained, that they are safer where they are, and that passing time and turmoil have made it impossible to determine rightful owners.

But in recent years, the scales have tipped.

“I think there’s been a big shift,” said Geoffrey Robertson, a British-Australian restitution expert and human rights lawyer, and the author of the 2020 book “Who Owns History?” “It started in a way with President Macron saying that Indigenous art, so much of which is in Western museums, should go back to Africa,” he said, referring to President Emmanuel Macron’s 2017 pledge to return France’s plundered African holdings.

In 2021, the German, Dutch and Belgian governments all announced plans to identify objects in museums that were looted during the colonial era and start the process of returning them. At least 16 U.S. museums have said they are engaged in the process of repatriating their Benin Bronzes, including the Smithsonian Institution and the Metropolitan Museum of Art in New York, and five more say they would be willing to do so if requested.

The increased scrutiny is not reserved for colonial plunder. Many institutions are reassessing their handling of artworks believed to have been stolen by the Nazis, who looted cultural property from every territory they occupied, targeting Jews in particular, and ultimately amassing hundreds of thousands of objects. Many of those objects ended up in auction houses and museums across the world. According to the United States National Archives, upward of 20 percent of all European art was looted by the Nazis.

Last year, New York State passed a law requiring museums to identify art stolen by the Nazis on placards “prominently placed” alongside the art. Last February, the decision of a committee in the Netherlands to return a Kandinsky to the family of a Jewish woman who most likely owned it before the Holocaust is the latest decision in that country favoring restitution.

And this year, the descendants of a German-Jewish collector filed suit against the Solomon R. Guggenheim Foundation for ownership of a Picasso masterpiece that the collector sold after fleeing Nazi Germany on the grounds that the sale was made under duress.

In Germany, over the last 10 to 12 years, Mr. Lupfer said that museum professionals have largely gone from fighting to retain contested holdings to “realizing that it’s absolutely necessary— it’s ethically, politically, socially necessary— to make restitutions.”

Which is not to say that all European museums came to that conclusion easily. The Leopold Museum in Vienna, which was formed from the private collection of Rudolf and Elisabeth Leopold, has long been shrouded in controversy regarding Nazi-looted art.

In 1998, the Manhattan district attorney served a subpoena to the Museum of Modern Art, ordering it to hold two Egon Schiele paintings on loan from the Leopold after a New York Times investigation uncovered their disputed ownership. Later, an independent 2008 study found that numerous artworks in the museum had belonged to people persecuted by the Nazis, and that Dr. Leopold, who died in 2010, had reason to suspect they had been looted.

After years of sparring in the courts, the museum reached settlements with the heirs of the original owners of 11 artworks, including one of the two seized in New York. Contested paintings are now displayed with labels explaining that they were taken from Jewish owners by the Nazis.

Hans-Peter Wipplinger, the director of the Leopold, emphasized in a statement that the museum has prioritized provenance research since its inception, and in 2003 commissioned an in-house researcher, whose work was complemented by the independent panel beginning in 2008.

“By the end of 2020, the independent provenance researchers had concluded their research into the core collection of the Leopold Museum,” Mr. Wipplinger said, noting that they “have been unable to identify further works from the Leopold Museum’s collection with a history of confiscation during the National Socialist era. Should such works be identified in the future, the Leopold Museum Private Foundation will seek and implement a ‘fair and just solution.’”

But critics say that provenance has still not been established for more than 90 percent of the artworks in the museum, which is a private collection and not beholden to Austria’s federal restitution guidelines.

Visitors, many of whom have traveled from afar to see the world’s largest collection of Schieles, have to reckon with the knowledge that the art they are viewing might have been stolen from Holocaust victims.

‘Much more than just art pieces’

There is no institution that’s faced more controversy around colonial acquisitions than the British Museum, which was the first public national museum to cover all fields of knowledge when it was founded in 1753 in London. It is home to around eight million objects, many of which were acquired during the centuries-long rule of the British Empire.

“I’ve described the British Museum as the world’s greatest receiver of stolen property,” said Mr. Robertson, whose book lays out a case against the museum’s resistance to returning colonial plunder. “Tourists should bear in mind that much of the interesting ethnic stuff that’s on display is, in fact, stolen, often at the end of a musket.”

When I visited the museum recently, lines snaked around the block. The museum was thronged with visitors who had come to see its marvels of human civilization, including the Rosetta Stone (removed from Egypt by the British in 1802) and jade treasures from the Summer Palace in Beijing (sacked by British and French forces in 1860).

Visitors crowded into the Greek galleries to see what is probably the most contested holding, the Parthenon Marbles — or Elgin Marbles as they are sometimes called, after the British aristocrat who had them removed from the Acropolis of Athens in the early 1800s. A collection of Classical Greek sculptures dating from the fifth century B.C., the marbles have been the subject of public acrimony almost since the moment they were taken (Lord Byron wrote a poem about their removal in 1811).

Although the British Museum has been in talks with the Greek authorities about a possible settlement for more than 30 years, the museum has held steadfast, arguing, among other points, that Lord Elgin purchased the marbles legitimately from representatives of the Ottoman Empire, which occupied Greece at the time. Restitution proponents counter that the Ottomans were invaders who could not legitimately sell off the country’s heritage.

Museums have long relied on legalistic conventions, presenting sales receipts for the contested items, or documents declaring that they were handed over legally, but critics say these formalities masked coercion and theft.

“It is a very difficult discussion, and the question, ‘Did he acquire it lawfully?’ won’t bring you much further,” said Evelien Campfens, a legal scholar specializing in art and cultural heritage law at Leiden University in the Netherlands. “You can see this even with Nazi-looted art, with sales to a Nazi officer where there was money involved. Was that legal? Well, under the legislation at the time, it was lawful, but we do not think that’s correct today.”

With cases involving colonial-era objects or religious artifacts that are still of cultural importance to people today, Dr. Campfens said, “It’s clear that it’s not just a commodity that we’re talking about.”

At the British Museum, under a Parthenon frieze, a Greek family posed for photos in front of figures of gods and heroes. As in Berlin, accompanying explanations acknowledged the sculptures’ contested provenance, but here, no plans were announced to return the artworks.

In their resistance to repatriation, officials often cite the British Museum Act of 1963, legislation that prohibits the trustees from removing items from the collection except under exceptional circumstances. The law would need to be changed by Parliament, although some restitution experts have argued that it is vague enough to give the trustees leeway.

Demands for the marbles’ return have intensified since the opening in 2009 of the Acropolis Museum, at the foot of the ancient Acropolis, where the British-held Parthenon Marbles would be reunited with those that remain in Greece. Secret talks over the past year between Greece and the British Museum are an encouraging sign that the dispute could be nearing resolution, though officials on both sides have made it clear that no deal is yet in sight.

“Discussions with Greece about a Parthenon Partnership are ongoing and constructive,” said a British Museum spokesman in a statement to The New York Times. “As the chair of trustees said recently, we operate within the law and we’re not going to dismantle the museum’s collection as it tells the story of our common humanity. We are however looking at long-term partnerships, which would enable some of our greatest objects to be shared with audiences around the world.”

As I wandered through the museum, I encountered, again and again, visitors who not only were aware of the contested provenance of some exhibits, but were connected to the countries from which works had been plundered.

“These are much more than just art pieces,” said Ayodeji Onime, a Nigerian of Edo ethnicity visiting the Africa galleries, where the museum displays artifacts from the Kingdom of Benin. Knowing how they were taken “through bloodshed” makes the experience of viewing them painful, Mr. Onime said. He gestured toward painted wooden effigies, or ikenga, made by the Igbo people of southeast Nigeria. These works “have a spiritual connotation,” he said. “It’s like a part of our ancestors have been snatched or stolen away.”

“I don’t think that they should take things away from the native place,” said Isidora Labbé, a 23-year-old Chilean who had come to see Hoa Hakananai‘a, an ancient basalt statue, or moai, taken in 1868 by the crew of a British ship from Rapa Nui, or Easter Island, a Chilean territory in Polynesia. “For the people in the island, this is a very important thing,” Ms. Labbé said. “It’s a keeper of peace and security.”

A new museum concept

The fact that the British Museum is one of the world’s great attractions, where anyone can view, in one place, the achievements of human history, is one argument against repatriation. But consensus is building that such an attraction should not come at the expense of cultural plunder. Meanwhile, new projects, like the Edo Museum of West African Art in Nigeria, where repatriated artworks from historical Benin will be housed, are recasting conceptions of what an ethnological museum should look like.

A vast complex at the site of historic Benin City, the museum was conceived by the Ghanaian-British architect David Adjaye as “a kind of abstraction of how Benin City would have looked before.” Excavated through a joint archaeological project with the British Museum, the site will include a research and collections center, rainforest gardens and an artisans’ hall where contemporary craftspeople can sell their wares. The main museum building will be a riff on the old Benin Palace where visitors can view repatriated bronzes and learn about colonialism.

“You can walk through an area that has the nature as it would’ve been in those days, and you actually can see the ancient moats and walls,” said Phillip Ihenacho, a Nigerian financier who serves as executive chairman of the trust that owns and operates the project, which will begin its phased opening next year. “You will understand that this isn’t about an ancient civilization that died. The tradition of craftsmanship exists today. It has been passed down.”

Perhaps most crucially, Mr. Ihenacho said, the project offers a hopeful narrative to the local population. “When they understand how sophisticated, how advanced and how great the Benin Kingdom was relative to what was happening in Europe at the time, it can give people a sense of optimism for the future,” he said. “There is a way to talk about how things could be.”

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