Claude Monet’s late-period paintings, once met with skepticism by much of the French art establishment, are set to be exhibited and auctioned publicly for the first time, highlighting the vision of an early admirer who recognized their significance decades ago.

Jeanne Schlumberger, head of a prominent French industrial family and a passionate supporter of avant-garde art, assembled a collection over more than 50 years that includes 28 works slated for auction at Sotheby’s Paris on October 22. This collection, valued at over €40 million, features notable pieces by Monet alongside works by Gustave Moreau, Paul Cézanne, Camille Claudel, and Gustave Courbet.

The centerpiece is Monet’s monumental painting Iris, the final canvas in his renowned series, completed in 1925, a year before the artist’s death. Measuring on a scale unmatched by any other late work remaining in private hands, Iris is expected to fetch between €22 million and €30 million. The painting reflects Monet’s late-career shift from traditional landscapes to a more abstract representation focused on atmosphere, space, and time, according to Marianne Mathieu, an art historian and former head curator at Paris’s Musée Marmottan Monet.

“Monet no longer painted landscapes, but atmosphere, space and time,” Mathieu said. “Iris is an extraordinary expression of this. The iris stems rise upwards, yet appear to emerge from a single expanse in which water, sky and reflections fuse together, enveloping the viewer in light, colour and sensation.”

Despite acclaim for his earlier impressionist works, Monet’s late paintings, characterized by their large scale, loosened composition, blurred forms, and intensified colors, were often criticized during his lifetime. He ceased exhibiting new works after 1912, and many of his late canvases were only publicly seen after his death. It was not until the 1950s that critics began to reevaluate these pieces, drawing connections between Monet’s late style and emerging trends in abstract expressionism.

Thomas Bompard, co-head of modern and contemporary art at Sotheby’s Paris, highlighted Schlumberger’s foresight in collecting Monet’s late pieces at a time when they were largely overlooked in France. Encouraged by Parisian art dealer Katia Granoff, the two recognized these works as precursors to modernism and abstraction.

Among the other notable works unveiled for the upcoming auction is Monet’s Saule pleureur (Weeping Willow), estimated between €8 million and €12 million; like Iris, it has never before been displayed publicly.

“The undisputed masterpiece of the collection is Iris,” Bompard said. “A century after it was painted, it still seems modern.”