In the 1960s, art dealers and publishers Aimé and Marguerite Maeght decided to create a private foundation that would showcase their collection, based on models they had seen in the United States. They were encouraged by Cubist artist Georges Braque who saw in the project a way for them to cope with the loss of their son Bernard, who died of leukemia in 1953. The first of its kind in France, the Fondation Maeght opened in July 1964. At its inauguration, then minister of culture André Malraux said, “This is not a museum, but a place made from love and for the love of art and artists.”

Today, the museum is home to some 13,000 objects, including 2,000 works by Joan Miró (the largest collection in France), as well as site-specific installations by Braque, Pierre Tal-Coat, Marc Chagall, Pol Bury, Germaine Richier, and Alberto Giacometti, whose sculptures fill the courtyard.

Closed on and off for the past seven months, the Fondation Maeght reopened its long-awaited expansion last month. “We had the idea for the expansion in 2004. It was what my grandfather wanted, but we could not find the right person for the job,” said Isabelle Maeght, the Maeghts’ granddaughter, during a press conference.

Designed by Paris-based firm Silvio d’Ascia Architecture, the new section adds 5,005 square feet to the museum’s footprint, without disturbing the original architecture by Josep Lluís Sert, who also built Miró’s studio in Mallorca. Instead, d’Ascia chose to dig four extra galleries under the existing building; the largest of which lies below the Giacometti courtyard. (They are only visible from the Chemin de Rondes, which runs behind the museum.) The largest one lies below the Giacometti courtyard.

“This is an extension project by subtraction,” d’Ascia said during the press preview. “As an architect it is important to know when to set one’s ego aside, especially in the face of an invisible project. I had to adopt a silent approach not to disrupt the foundation’s already perfect balance.”

These new underground galleries overlook a pine forest and the Mediterranean Sea, thus keeping alive the dialogue between art, nature, architecture that served as the foundation to the Maeghts’ vision for their museum.

Adrien Maeght, 94, the Maeghts’ son and current president of the foundation, added, “The basement rooms designed by Silvio d’Ascia have brought the site into the 21st century.”

The expansion will now allow the foundation to display its permanent collection (downstairs in the expansion) alongside temporary exhibitions (upstairs in the original building), like its current one for Henri Matisse and Pierre Bonnard. The new “Galerie de la Bibliophilie” opens the renovated building, showcasing selections from the 45,000 books in the foundation’s collection. Down a dozen steps are paintings by Pierre Soulages, Jean Paul Riopelle, Jean Messager, Fernand Léger, and others. The final room is dedicated to recent acquisitions, including a figurative painting by Hélène Delprat, who will be the subject of a solo show at the foundation by next spring.

The budget for the expansion project amounts to €5 million, including €1 million from Adrien Maeght and €500,000 each from the French state, the Provence-Alpes-Côte d’Azur region, and the Alpes-Maritimes department. The Dassault family also gave €1 million, through their “History and Heritage” fund, managed by the grandchildren of Marcel and Madeline Dassault who were friends of the Maeghts and attended the foundation’s 1964 opening. The company Triverio, which oversaw the original building’s construction 60 years ago, participated as corporate sponsors. “Without friendship this foundation would not even exist,” Isabelle Maeght said several times throughout the preview.

The theme of friendship also played a role in the Bonnard-Matisse exhibition, as both artists were friends with the Maeghts. “Bonnard and my father first met in Cannes in 1936 through a lithograph to be printed,” Adrien Maeght writes in the exhibition catalog. Bonnard then introduced Aimé Maeght to Matisse in 1943, but they only became close after Matisse and Marguerite randomly met in a doctor’s waiting room; “a man sat down next to her and asked her to pose for him,” and she soon became his “active agent.”

Today, about 40 drawings of Marguerite by Matisse remain; several of them are featured in the new collection hang. “At the age of fourteen,” Adrian continues in the catalog, “I had the privilege of attending one of these posing sessions and of making an eight-minute film—the only document I know of showing Matisse drawing.” Also on view is Matisse’s Le Buisson (The Bush), which hung above Bernard’s bed during his illness.

Featuring both artist’s landscapes and visions of Saint-Tropez’s light, self-portraits and several portraits of their recurring models, the exhibition mostly avoids pairing works by Bonnard and Matisse side by side. That’s intentional, according to the show’s curator, Marie-Thérèse Pulvenis de Sévigny, a former conservator at Nice’s Musée Matisse. The focus here is on the Maeghts and their relationship to the artists: Bonnard encouraged them to open a gallery in Paris, and Matisse was chosen for the inaugural show in 1945. “What matters here is the synergy between the three, which served as a springboard for the foundation,” she said.