As a child, Marc Glimcher often accompanied his father, the gallerist Arne Glimcher, founder of Pace Gallery, in his rounds to meet with artists. He was 11 or 12 on a trip to Paris when they called on one of Pace’s headliners, Jean Dubuffet. “You had to call him Maître,” Marc recalled one day this past June during a tour of the new Pace building in Chelsea, which is opening on September 14. As he and his father walked among a group of Dubuffet’s paintings, the irascible artist, who was in his 70s, asked young Marc which he liked best. The boy pointed to one of the compositions. “Why?” Dubuffet asked. Marc considered for a moment. “Because it is the most beautiful,” he said.

Dubuffet whacked him on the back of the legs with his cane. “Try again,” he said.

Fighting back tears, Marc thought it over. “Because it’s the most ugly,” he said.

Dubuffet smiled. “Good boy,” he said.

Marc, who will soon turn 56, recalled the encounter with a chuckle. “And that’s where I learned to be an art dealer.”

We were standing on the gallery’s sixth-floor outdoor sculpture space; its black locust flooring had brought the memory to mind. Marc first saw the wood, tough as cobblestones, in the courtyard of the venerable Parisian art-storage facility where he met Dubuffet. He recommended it to the Pace architects for the new building, which affords 16,500 square feet of exhibition galleries and more than doubles Pace’s current footprint in New York. The new Pace headquarters theatrically signals the passing of control of one of the world’s largest and most respected art galleries from father to son.

Jean Dubuffet’s Chambre au Lit Sous l’Arbre (Room With a Bed Under the Tree), 1973, in Arne and Milly Glimcher’s garden in East Hampton, New York—the artist gave it to Arne on the condition that he pay to have it shipped from Paris.

Photograph by Martien Mulder.

Milly, Marc, and Arne, in the performance gallery of the Pace headquarters in New York.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski.

If mollifying artists were all it took, Marc might have grabbed the helm of Pace with greater speed and less drama. Instead, his succession path has been almost as tortuous as Oedipus’s. Rumpled, voluble, and outgoing, Marc comes across as the opposite of his dapper, buttoned-up father. “Arne cuts an extremely elegant figure,” says Alexander Rower, a close friend of Marc’s who is chairman and president of the Calder Foundation, which oversees the legacy of his artist grandfather. “Marc is much more concerned with the brain than the body.”

As he is the first to admit, Marc started his ascent from a privileged position. “I was born not with a step up but with a jet pack,” he said. And yet, he continued, the obstacles he faces are daunting. “There’s a founder’s personality cult. ‘What are the odds that his kid can do it?’ Yes, the hard work has been done. But you have to be as hardworking, charismatic, inspirational as your father, without getting into a cycle that destroys the company—but also without continuing with just what already exists.”

What exists is impressive. Marc is inheriting a gallery that represents many of the leading modern and contemporary artists and estates: Mark Rothko, Alexander Calder, David Hockney, Chuck Close, and Julian Schnabel, among many others. And the roster keeps growing: Over the summer, the innovative, venerable African-American abstract painter Sam Gilliam joined the fold. The inaugural shows in the new building will celebrate some of those heavy hitters: a panoramic 24-panel drawing by Hockney of the landscape around a country house in Normandy he recently acquired; a Calder show that examines the years that led up to the first mobile sculpture in 1931; and five of the Murano glass chandeliers that Fred Wilson has created since 2003. Looking toward the future, the opening lineup will also include the Pace New York premiere of young artist Loie Hollowell, whose semiabstract paintings explore sexuality and the female body through geometric forms.

Milly, Arne, Fairfax Dorn, and Marc on the steps of the Dubuffet work. Dorn wears a Loro Piana dress. Marc wears a Brunello Cucinelli shirt; Loro Piana shoes. All other clothing their own.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski.

Arne Glimcher had himself envisioned a career as an artist. Born in Duluth, Minnesota, in 1938, he grew up in a comfortably middle-class home in Boston and, at 21, enrolled in the M.F.A. program at Boston University, where Brice Marden was a fellow student. Arne’s new wife, Milly, was studying art history at nearby Wellesley College. And then his father, who had owned and operated a cattle ranch in Minnesota, died. The funeral was on a Friday. The next day, to raise their spirits, the family went on a tour of Boston’s Newbury Street art exhibitions. They passed an empty storefront, and Arne remarked that it would be a good place to open a gallery. Do it, urged his businessman brother, Herb, who is 11 years older. He staked Arne $2,400. Named for their father, Pace Gallery opened three months later, in April 1960.

By 1963, Pace had moved to New York; the Boston space closed in 1965. “This whole thing was started without a plan,” Milly told me. “But we knew that we had to move to New York if Arne was going to be a serious art dealer.” Having given Louise Nevelson her first Boston show, Arne parlayed the artist’s loyalty—soon amplified by the representation of Robert Irwin, Lucas Samaras, and Dubuffet—into a solid foundation. Then and now, he regarded himself as a curator more than a salesman. He is justifiably proud that Pace inaugurated the trend of museum-quality shows in commercial galleries, often with few if any works for sale. Two Picasso exhibitions—of late paintings in 1981 and sketchbooks in 1986—set the standard. Pace also led the way for galleries to publish scholarly catalogs. Of course, such projects, uncommercial on the surface, could serve the bottom line indirectly by attracting artists and artist estates to the gallery. “When we would go to see an artist, we would bring a stack of catalogs,” said the private dealer Jeffrey Hoffeld, who became a vice president of Pace in the early 1980s. “That is not something that was historically done.”

Marc and Arne inside Dubuffet’s Chambre au Lit Sous l’Arbre. Marc wears a Brunello Cucinelli shirt.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski.

In one of his proudest (and most publicized) achievements, Arne put together a deal in 1980 that raised $1 million to buy Jasper Johns’s Three Flags for the Whitney Museum of American Art. A record for a living artist, the sale made the front page of The New York Times and was a splashy sign that contemporary art was overtaking Old Masters in pricing and buzz. Despite the benefit for Pace, Arne—a man of driving ambition and unshakable self-confidence—insists that he prefers to avoid the limelight. “I think the artists are the stars, and I hate the way the dealers have become the stars,” he said recently, still ensconced in the office on East 57th Street that he was about to give up, not without regrets, when the gallery transferred all of its New York operations downtown. Pace has been headquartered in midtown New York since leaving Boston. “But people don’t come to 57th Street to see art anymore,” Milly said. In the more open territory of Chelsea, galleries are expanding dramatically. Outdoing Pace, a building under construction for David Zwirner will provide 50,000 square feet of exhibition space, and one planned nearby for Hauser & Wirth will have 35,000.

When Pace opened in New York, the leading American art dealer was Leo Castelli. “Arne initiated the professionalization of the art business, with more employees, a little more structure,” said Douglas Baxter, a president of Pace. “Until then galleries had three or four or five employees, and their roles were not well defined.” Pace also took the lead in creating branches in other cities, opening in Beverly Hills in 1995. But it had an aggressive rival. That year, Larry Gagosian, who had started out selling posters in Los Angeles and opened in New York in 1985, also established a Beverly Hills outpost. By this time, the momentum was with Gagosian, whose swashbuckler reputation contrasted with Arne’s low-key style. Underlining the difference, Pace in 1993 merged with the venerable French family firm of Wildenstein & Co., the preeminent dealer of Impressionists and Old Masters, which bought 49 percent of Pace to form PaceWildenstein. “I rejected the idea for about 10 years,” Arne said of the merger. But by then, Marc, the younger of his two sons, had joined the gallery. “When Marc thought it would be a good idea, I thought maybe it would be useful to have the history of art at our fingertips and give our clientele that range.” (The partnership came to an end in 2010, as the contemporary art market emphatically eclipsed the one for Old Masters.)

Marc had first joined Pace in 1985, after graduating from Harvard. But in 1989, he enrolled at the Johns Hopkins School of Medicine to pursue research in immunology. His first wife, Natalie Geary, was studying there too, to be a pediatrician. Even though Arne took his two sons to an art museum every Saturday and supervised their drawing efforts in the kitchen after Hebrew school on Sunday, he didn’t want them to enter the family business. (Paul, the older son, is a distinguished neuroscientist.) “When the children were little, I would say to them, ‘I’ll support you in anything you want, except coming into the Pace Gallery,’ ” Arne recalled. Still, when Marc, disenchanted with life in the laboratory, called his father in late 1991 and asked to return, Arne couldn’t say no.

In the late 1980s and ’90s, Arne ventured into the movie business, which had long fascinated him. He has produced or directed seven films, including 1988’s Gorillas in the Mist, starring Sigourney Weaver, and The Mambo Kings, in 1992. He never lost touch with Pace, but in comparison with the aggressively expanding Gagosian and the younger galleries of David Zwirner and Hauser & Wirth, Pace seemed to be treading water. Between 1994 and 2004, the gallery took on only one new artist, Alex Katz (who subsequently departed for Gavin Brown’s Enterprise). “The gallery could have died so easily at different points in the late ’90s,” Marc said. Asked if the gallery might have closed, Arne said, “I thought it was an option.”

Milly and Arne’s matching tattoos of each other’s initials, which they got to celebrate their 50th wedding anniversary.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski.

Milly and Arne’s matching tattoos of each other’s initials, which they got to celebrate their 50th wedding anniversary.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski.

Marc felt he was ready to take over. He advocated for the Wildenstein merger as a step toward weakening Arne’s control. “It was just another way to exit my father,” he admitted. The tension between the upstart son and the tenacious dad ratcheted up relentlessly until, in 1997, the band snapped. “My mistake was believing I was ready to take over,” Marc reflected. “My father believed that I was not, and he was correct. He still had complete control of the gallery. I couldn’t stand that. I said, ‘This town isn’t big enough for both of us.’ He said, ‘Okay, here’s the door.’ I walked through it.”

He found a job as a second-grade science teacher in Santa Fe, moving there with Geary, who operated a mobile pediatric medicine service out of an RV, and their two daughters. After a couple of years in New Mexico, they packed off to Malawi to assist in combating the AIDS epidemic but lasted just four months. By that time, Marc’s marriage was in trouble and he was in a state of reassessment. He asked his father if he could return. “I loved my life with the artists, as much as a pain in the ass artists can be,” he explained. Indeed, the main reason he had chosen New Mexico for the family relocation was to be near Agnes Martin, whose sage-like counsel he revered.

He proved himself to his father through his ability to sell. “The core of our business is selling the art,” Marc said. “Unless you can go from the artist’s studio to the collector’s home and transmit the artist’s vision, you can’t run a gallery.” The artist Adam Pendleton recalls that at his first Pace show, in London in 2012, he tagged along on the walk-through as Marc described to the sales directors how Pendleton’s “Black Dada” paintings related to the work of Ad Reinhardt, Robert Rauschenberg, and ­Robert Ryman. “He spoke about the paintings very well. And then he said, ‘These are precious things, and if you are trying to sell them to someone who doesn’t understand that, it’s not for them. Move on.’ ” Pendleton was pleased.

Pace quickened its step in the 2000s, notably when Arne opened a branch in Beijing in 2008, the first major Western gallery to do so. “He was always a sinophile,” Marc said. “And he realized that great art was always being made at a time of great social turmoil.” Although the Beijing gallery shuttered in July, a victim of president Xi Jinping’s art-sales tax and crackdown on conspicuous spending, and of Donald Trump’s tariffs, there are now Pace branches in London, Hong Kong, Seoul, Geneva, and Palo Alto. “Marc always said to Arne that the art world had changed and expanded, and he had to accept that,” Milly said. Gradually Arne did. By the time of Pace’s 50th-anniversary celebration, in September 2010, Arne told Marc he was ready to start relinquishing control. “Marc used to work for me, and now I work for him,” he told me. Their relationship can be prickly, but it is loving and mutually respectful.

Arne and Marc take in the view of Manhattan’s Chelsea neighborhood and beyond in Pace Gallery’s seventh-floor performance space.

Photograph by Martien Mulder; Styled by Jenna Wojciechowski. Hair by John Ruidant for R+Co at See Management; Makeup by Robert Reyes for Chanel at MAM NYC; Photography assistant: Ross Zavoyna; Digital technician: Dallas Raines; Special Thanks to Edge Auto Rental, Jack Studios, and Root Brooklyn.

Adding to Marc’s contentment is his third marriage, in 2015, to Fairfax Dorn, 44, who hails from a wealthy Texas ranching family and is the cofounder of the Ballroom Marfa, a nonprofit organization in the West Texas art-and-cattle town. Although Marc speaks admiringly of his two previous wives (the second, Andrea Glimcher, runs an artist management firm.), he says that “Fairfax without question helped me to evolve to a level of maturity.” Under her influence, Marc practices Vedic meditation for 20 minutes twice a day. “That was a prerequisite for our marriage,” Dorn told me, laughing. “He’s always been on ‘go.’ ” Dorn is also helping to select antique and modernist furniture for the Chelsea space. “The nonprofit world is also about hospitality,” she said. “I know Marc was thinking, How do we make it feel welcoming to all? I think he was probably somewhat inspired by what I created at Marfa.”

The new building has a spectacular live-performance space on the seventh floor that can seat 300 (Pace plans to sell tickets to cover costs) and a first-floor research library that will admit visitors by appointment. On the second floor, an open storage facility is intended to give the public access, also by appointment, to works on sliding racks. “People want to go poke around in the back,” Marc said. “We have cut the velvet ropes as much as possible. We think that is the way to go today.” While collectors of his father’s generation may have viewed owning major artworks as a way of distinguishing themselves, those his age and younger, he believes, are looking for art to provide connections to the larger world. The new Pace flagship represents Marc’s vision of how an art gallery should operate today and in the future. “Here we are, trying to push the edge of what we can be,” he said. He hopes that under his tenure, the building becomes not just a monument but a beacon.