BENIN CITY, Nigeria — The young artist flipped through grainy photographs of delicate ivory masks of Queen Idia, seeking inspiration for her own painting of the legendary warrior queen. The masks were made around 500 years ago by a carvers guild just around the corner from the studio where the artist, Osaru Obaseki, worked.
Five of these ancient masks are known to exist. But Ms. Obaseki has never seen one. None are in Africa, let alone in Benin City, her hometown in southern Nigeria. One of the most exquisite is in a display case in a basement of the British Museum in London. Another is in the Africa gallery in New York’s Metropolitan Museum of Art.
These and more than 3,000 other works — and perhaps thousands more as well — were stolen by invading British soldiers in 1897, and are now treasured pieces in the collections of some of the most important museums in the United States and Europe.
For years, Nigeria’s artists, historians, activists and royals have been clamoring to get these pieces back. And, as conversations about racism and the legacy of colonialism have proliferated globally in recent years, some institutions are beginning to respond to these calls.
But many Nigerians are outraged that only a fraction of these treasures are even under discussion for return — and not even the most cherished ones, like the Queen Idia masks.
To them, the stolen works are not just physical objects of art, but narratives. They form part of the bedrock of the identity, culture and history of Benin — the city in Nigeria that was once part of the Kingdom of Benin, not the modern nation Benin.
“They were made to tell stories, to keep memories, and to hand over all these stories and memories from one generation to another,” said Enotie Ogbebor, an artist from Benin City and the founder of Nosona Studios, where Ms. Obaseki works. Western institutions had turned these pieces into “objects of admiration, when these were objects holding information,” he added.
Some of the artifacts — known as the Benin Bronzes, although most are made from brass and some from wood and ivory — were religious objects, used in shrines. The oba, or king, would carry masks like the ones of Queen Idia during important ceremonies. A series of intricate bronze and brass plaques, some of which now are displayed across a wall in the British Museum, each told a piece of the kingdom’s history, together making a cohesive narrative.
For years, museums have resisted restitution of foreign treasures. The Metropolitan Museum of Art, the Louvre and 16 others argued in 2002 that global collections like theirs served “the people of every nation.” In Europe, where collections often belong to the state, museums have often said that decisions don’t rest with them.
The British Museum has previously floated the idea of loans, but never full restitution. The Met was not considering sending its Queen Idia mask back, said Kenneth Weine, a spokesman. No other institution has said it would return one of those masks either.
Restituted works are likely destined for a new museum in Benin City, to be called the Edo Museum of West African Art. It is designed by the architect David Adjaye and planned for completion by 2026, if the creators can raise around $150 million. A digital project will bring together photographs and oral histories of the looted objects.
At the moment, there is little to see at the planned museum site beyond red earth, an abandoned hospital and some damp-stained walls. Before building begins, there will be a major archaeological dig, funded in part by the British Museum, to excavate the buried remains of the old city.
For now, Benin City’s existing museum is a small building in the center of a busy junction that receives scant funding from the government and that cannot always afford to keep the lights on.
Inside its red walls are a few lonely plaques and a picture of a Queen Idia mask. One whole wall is taken up with a blown-up photograph from 1897 of British soldiers sitting, smoking cigarettes, surrounded by their loot.
In Britain, the events of 1897 are known to many as the Punitive Expedition. According to this version of the story, a party of British officers came to Benin to meet the oba, but were killed. So the British dispatched 1,500 men, some armed with early machine guns, to avenge their deaths.
But in Nigeria, it is known as the Benin Massacre, because of the many residents the British forces killed. The British were looking for excuses to attack Benin, Nigerian historians say, because the oba had too much power. And the soldiers knew that Benin contained untold riches; they said so in letters home.
They took most of those riches.
It was “the equivalent of taking the works from the Renaissance in Europe all the way to the modernists,” said Mr. Ogbebor the Nosona Studios founder. “Bach, Handel, Shakespeare, Mozart — everybody. That’s what was done to us. Imagine if that was taken away from Europe for the last 130 years. Do you think Europe would be where it is today?”
Theophilus Umogbai, curator of Benin’s museum, agreed. “It’s like burning down huge libraries,” he said.
The treasures are expected to be returned to a trust that aims to bring together the current oba — the descendant of the king deposed in 1897 — and regional and national governments although some internal disagreements between them need to be worked out. (For example, the oba said, in a written statement to the media, that he should be the sole recipient of the treasures, and that anyone working with the trust is “an enemy.”)
Over the past decade, knowledge and outrage about the looting of the Benin art works has deepened.
In a 2010 survey of Benin City residents from market women to politicians, Kokunre Agbontaen-Eghafona, a professor of cultural anthropology at the University of Benin found that only about half of respondents knew that the works were stolen by the British. This year, a pilot study for a planned repeat survey showed that awareness has jumped to about 95 percent.
“They are aware,” she said. “And indeed, they want the restitution of our objects.”
The treasures, though long absent, are still woven into daily life. A tailor in the old city keeps a picture of Queen Idia tacked to his wall, inspiring his designs. In the grand home of John Osamede Adun, a Benin City businessman, a shrine is tucked away in a corridor, with a few bronze royal heads, era undetermined.
“They are our ancestors. Our fathers, our grandfathers,” said Mr. Adun, flicking on a light to reveal dozens more bronzes in his stairwell.
“In the night, they wake up and talk,” he said. “I know the language to use for them.”
Some members of the ancient bronze casters’ guild still practice their ancestors’ craft.
One afternoon in May, men of the ancient Aigbe foundry prepared to cast, one tossing bits of scrap metal — an old radio antenna, a bracelet — into a crucible emanating green smoke, while another stoked a fire around hunks of red earth held together with wire.
The Aigbe family has been casting bronze for so long that, they said, one of the plaques stolen in 1897 was made by an ancestor.
The young artists working in Nosona Studios, which is in a crumbling former supermarket, have blackened the windows that overlook the old museum and, beyond, the oba’s palace. The modern city, with its hooting cars, its Afrobeats thrum, its hawkers selling padlocks and mangoes from wheelbarrows, reminds them of what Benin could have been, but for the events of 1897.
Derek Jombo, the first artist to paint over the windows, said he can’t bear to look out.
“I’m aware of what this town should be,” he said.
Ms. Obaseki, the artist, longs to be able to look at Queen Idia masks from different angles, and see their exact hues.
“It’s quite different when you are looking at an object physically and you see all sides to it,” said Ms. Obaseki, who is 28. She took a handful of the burned sand she was using, collected from a bronze casters’ foundry, and let it run through her fingers.
Ruth Maclean reported from Benin City, Nigeria, and Alex Marshall from London. Sarah Bahr contributed reporting from Indianapolis, and Zachary Small from New York.