“T he sale of such works, gives us the opportunity to tell the stories of the people that owned these pictures,” says Lucian Simmons, Vice Chairman and Sotheby’s Worldwide Head of Restitution who has worked with many heirs and families, reuniting them with property stolen between 1933 and 1945.

Sotheby’s has been a leader in the field of restitution and provenance research since it launched the department in 1997. “We are still the oldest and most long-standing department in the commercial art market, and we work closely with museums and other institutions as part of a wider research community,” Simmons adds.

Indeed, the auction house has been actively involved in initiatives around Nazi Era-looted art for more than 25 years. “We attended the Washington Conference in 1998 [concerning the restitution of art confiscated by the Nazi regime] as observers and have been at the table in every major policy discussion in the field since that time,” Simmons says.

He outlines how the department has developed. “In 1997 there was an increased focus on art displaced during World War II and we developed a due diligence program to reduce the risk that Sotheby's might offer a looted artwork for sale. Stage two, in the early 2000s involved working with families and brokering settlements between families and heirs. It is a virtuous circle because of the process we go through in researching consigned works; crucially it gives buyers trust and enables us to apply the highest standards in the commercial marketplace.”

This commitment and expertise underpins various global projects. Last year Sotheby’s and the Louvre in Paris joined forces on a scheme researching items acquired by the museum between 1933 and 1945. The partnership, which lasts three years, will help fund research that may lead to restitutions incorporating digitisation, the organisation of seminars, study days, and publications, the Louvre says.

“It was an opportunity to give back and to help finance the digitisation of World War II era records so that the Louvre can more easily research its own collections and holdings,” says Simmons. “It is all part of our aim to be good actors in this space.”

In recent months, Sotheby’s has moved forward on a number of notable restitution sales and projects. Bronzino’s Portrait of a young man with a quill and a sheet of paper, possibly a self-portrait of the artist (around 1527) nearly doubled its high estimate of $5m to achieve a record-setting $10.6m at Sotheby’s New York in January. The painting was restituted from the German government to the heirs of the Munich-based Jewish collector Ilse Hesselberger; sale proceeds went towards Jewish causes and medical aid in New York.

On 1 March, a recently restituted painting from early in Wassily Kandinsky’s career is estimated to sell for around $45m when it goes to auction at Sotheby’s London. The work—Murnau mit Kirche II (1910)— heralding the artist’s abstract vocabulary is one of the most important paintings by Kandinsky to ever come to market.

Crucially, the proceeds of the sale will be split between 13 heirs of the painting’s former Jewish owners, Johanna Margarete and Siegbert Stern, a celebrated German-Jewish couple at the heart of Berlin’s glittering cultural life in the 1920s who mixed with luminaries such as Thomas Mann and Albert Einstein. The pair built up an eclectic collection featuring works by the Dutch Old Masters and Modern stars such as Max Pechstein.

Siegbert died of natural causes in 1935 but Johanna Margarete fled Germany in 1935 to escape Nazi persecution. She was captured in the Netherlands and deported to Auschwitz where she tragically died in May 1944. The Kandinsky work, on show at the Van Abbemuseum in Eindhoven since 1951, was restituted last year.

Proceeds from the painting’s sale will be split between 13 Stern descendants; the money will help fund further research into what happened to the rest of the family’s art collection, which included more than 100 works by artists including Pierre-Auguste Renoir and Edvard Munch. “The restitution to the heirs of Johanna and Siegbert has been especially resonant and moving, and we are so glad that the full story will now be told,” says Simmons.

Sotheby’s has also played a key role in bringing a monumental Munch masterpiece back to its original owners. Dance on the Beach, an energetic, expressive work depicting whirling couples at a shoreside party, features two of the artist’s greatest loves—Tulla Larsen and Millie Thaulow—in the foreground.

The work, offered for sale in the Modern and Contemporary Evening Auction at Sotheby’s London on 1 March, has a fascinating history worthy of a Netflix drama; the painting was part of a frieze of 12 panels commissioned in 1906 by Max Reinhardt for a theatre-in-round in Berlin. In 1912, the theatre-in-the-round was refurbished and the Munch frieze cycle was split up. Dance on the Beach was acquired by the curator, Professor Curt Glaser, who held the eminent position of director of Berlin State Art Library (he also published the first German monograph on Munch in 1917).

Simmons says that Glaser and his first wife regularly visited Munch in Oslo and, when Munch visited Berlin in the 1920s, he stayed with the Glasers. “So it wasn’t just a pure patronage relationship. Likewise, the Olsens had a house right next door to Munch’s house. This is a phenomenal picture and it has a phenomenal history,” he adds.

Glaser was however forced to sell the work in Berlin in 1934 while fleeing from the Nazis. Just months later, Thomas Olsen, a Norwegian shipowner and Munch’s neighbour, bought Dance on the Beach at an Oslo auction along with a number of other works by Munch. When World War II broke out, Olsen took his Munch pictures into hiding, concealing them in a barn in the Norwegian forest for the remainder of the war.

Dance on the Beach has been with the Olsen family ever since; as part of a unique agreement between the Olsen and Glaser families, the Expressionist masterpiece will be sold as part of a restitution settlement with the family of Curt Glaser. Simmons sums up meanwhile how his efforts make a difference. “It is wonderful as you can give back what the Nazis took away. You can breathe a little life into the owners’ legacy.”