“My Viennese heart is pounding,” says Max Hollein, director and CEO of the Metropolitan Museum of Art.

It’s pounding with joy over the coming merger of his institution with Ronald S. Lauder’s Neue Galerie New York, which holds the most extensive collection of 20th-century Austrian and German art—including Gustav Klimt’s famous Portrait of Adele Bloch-Bauer I, known as The Woman in Gold—outside of Europe. Not since Fred Astaire and Ginger Rogers has there been such a coupling.

Ronald Lauder and his brother, the late Leonard Lauder, are among the greatest benefactors in the Met’s illustrious history; Leonard donated his collection of 78 major Cubist paintings—by Picasso, Léger, Braque, and more—to the museum in 2013. For Ronald, collecting is also a labor of love; he’s been buying art by the German Expressionists and the Viennese Secessionists since he was a teenager.

Hollein and Ronald Lauder have been in conversation about joining the two museums for a year, and the Neue Galerie’s 25th anniversary—coming up this autumn—seemed like the perfect occasion for it. “For me, it’s personal,” says Hollein, who was born in Vienna and has been a Neue Galerie trustee for the last 20 years. “Its more than 600 objects, including masterpieces by Max Beckmann and Egon Schiele, adds great strength to the Met’s holdings. A visit to the Neue Galerie, like a visit to the Cloisters, is an entirely immersive experience—a gesamtkunstwerk.” Indeed, the merger—to be formalized in 2028—will also expand the Met’s campus to include the Neue Galerie’s landmarked Beaux-Arts mansion on East 86th Street; and Lauder’s gift will include 13 additional works from his and Aerin Lauder Zinterhofer’s personal collections.

“It’s a wonderful project that’s very dear to him,” says Lauder Zinterhofer, creative director of Estée Lauder and a recent Met trustee, of her father and the merger. “He really loves all different areas of art—arms and armor, Austrian and German, contemporary, old masters—so the Met is a wonderful partner in this project for him. And the idea of keeping this as a free-standing museum is something special for the Met.” Lauder has also enjoyed a long-standing relationship with Hollein. “My father has known Max for many many years—he was friends with Max’s father,” Lauder Zinterhofer says. “So there’s a wonderful connection there.”

Lauder Zinterhofer has memories of sitting with her father and his mentor, the art dealer Serge Sabarsky, in Sabarsky’s gallery on Madison Avenue when the Neue Galerie was still only an idea. “When I was little, my father used to walk me to Serge’s gallery. He would say to my mother, ‘I’m going to take Aerin to the park,’ and we would go to the park and then end up at Serge’s for hours and hours. I would color while they were discussing their dream of having a museum of Austrian and German art,” she says. When Lauder finally opened the museum in 2001, two months after the September 11 attacks, “it was a gift to New York—this jewel box.” All these years later, she says that he goes to the museum’s Viennese-style restaurant, Café Sabarsky, every Sunday for dinner.

Why join with the Met now? “I think the timing felt right,” Lauder Zinterhofer says. “My father is 82 and I had just joined the board. It was the perfect time to do it. And with Max as head of the Met, all the stars were aligned.” The Lauder family also sees, in the Met’s stewardship of the Cloisters, proof of its commitment to maintaining “the true intent of these institutions.”

“What's nice about doing this merger is it allows the Neue to continue for many, many years,” Lauder Zinterhofer says. “Because the Metropolitan Museum of Art is extraordinary and how they manage everything is beyond extraordinary.”

The Neue Galerie, Lauder Zinterhofer adds, will remain near and dear to its founder. “My father said he will still greet everybody as they come into the exhibitions.”