H & M’s collaborations with designers—including its first, with Karl Lagerfeld, in 2004—have helped erase the line between high and low fashion. Photograph by Becker & Bredel / ullstein bild via Getty

H & M launched its first-ever designer collaboration, with the Chanel creative director Karl Lagerfeld, eleven years ago, in November of 2004. My wife, a fashion illustrator, was sure something historic was in the offing, and she convinced me to go with her to check it out. We arrived at H & M’s flagship store, on Fifth Avenue, shortly before the doors opened, at 9 A.M. A line of men and women, ranging from twentysomethings to senior citizens, and dressed in everything from jeans to luxury labels, snaked down Fifth and around the block. Inside, they fought their way through the crowds, garments heaped over their arms; they stripped to their underwear in the aisles to try things on. In the melee, I managed to grab and try on a black military-style wool-and-cashmere overcoat. Cut long and slim, it elongated my frame, narrowed it, lent it a subtle drama that touched off fantasies of myself as a windswept Byronic wanderer (as opposed to a middle-aged deskbound writer). The price: a hundred and forty-nine dollars. A Lagerfeld original would have cost a thousand dollars. I bought two_._ I still wear that coat, and strangers still stop me in the street to ask where I got it. The backup, tags intact, is stuffed at the back of my closet, ready to be called into service when the original starts to look shabby.

My wife and I, not so incidentally, became regular shoppers at H & M. (Before that, we had never set foot in the place; that jaunty red logo seemed to scream cheesy Euro style.) The company, which had planned for the Lagerfeld collaboration to be a one-off event, made the designer collaborations an annual part of its fashion calendar, with subsequent collections by Stella McCartney, Viktor & Rolf, Comme des Garçons, Lanvin, Margiela, and Alexander Wang. This week, the chain débuted its collection with Balmain, the exuberantly decorative, sequin-and-embroidery-encrusted clothing line, whose creative director, Olivier Rousteing, I profiled recently in the magazine. The collaborations have proved invaluable to the company, as a way to promote its “brand recognition” and get people into its stores, but they have also helped revolutionize the luxury business, erasing the line between high and low fashion, and turning formerly rarefied fashion designers into something akin to mainstream celebrities.

Donald Schneider, who is now the creative director of H & M, came up with the idea of that first collaboration with Lagerfeld. At the time, Schneider ran a fashion-consulting firm hired by H & M to review its advertising campaigns, and he had worked for eight years as the art director of Vogue Paris. A soft-spoken German now in his mid-fifties, with glinting gray stubble and a bald head, he continues to dream up, and oversee, the collaborations today. When I met with him in June, at a photo shoot for the Balmain launch, I admitted that I had been among the hoards who lined up for the Lagerfeld début, and that I scored the black military-style overcoat. He nodded vigorously and said, “a fantastic piece,” adding that he is still wearing the suit jacket from that collection, and still gets compliments on it. Up to that point, he said, anyone who mentioned an H & M ad campaign would talk primarily about the models. “I wondered, could we do a campaign where people talked about the fashion?”

The idea of partnering with a fashion designer wasn’t totally new. In 1983, Halston, famous for his minimalist seventies party clothes, created a collection for J.C. Penney, featuring cut-price takes on his signature Ultrasuede disco wear. But the collaboration was ahead of its time, and the purveyors of high fashion were not yet prepared to see a luxury designer close the gap between couture and the masses. Bergdorf Goodman promptly dropped Halston, and his name (which he had licensed to J.C. Penney for millions) became a punch line. Not for another twenty years would a high-end designer dare (or deign) to partner with a discount retailer. In 2003—a year before the H & M-Lagerfeld collaboration—Isaac Mizrahi (whose own high-end line had folded five years earlier) agreed to create a collection for Target. By then, luxury designers, mining ideas from hip-hop and sportswear, had narrowed the gulf between high fashion and street clothing, and the mainstream public, schooled by popular TV shows like “Project Runway,” had developed an eye for sophisticated design. Mizrahi’s Target lines, which he produced for five years, were hugely successful, proving that the fashion world had come a long way since Halston’s misadventure. (Target, like H & M, would go on to produce collaborations with high-fashion labels including Alexander McQueen, Rodarte, and Proenza Schouler.)

For H & M, Schneider wanted to recruit a designer more successful and respected than Mizrahi or anyone else: he wanted the imperious high priest of haute couture himself—Lagerfeld. The company figured he would never do it. But Lagerfeld, who had been at the forefront of marrying high and low fashion (he had, starting in 1983, resuscitated Chanel by fusing youthful street looks—rapper chains, sneakers, micro-minis—with Chanel’s ladies-who-lunch jersey knits), agreed instantly. “He said, ‘Oh, that’s what I always wanted to do with the future of fashion—only high and low and everything in the middle disappears,’ ” Schneider recalled. “He only had one question. He said, ‘Am I the first one you’re asking?’ I said yes.”

Marketed with a barrage of billboards, magazine ads, and TV spots that featured Lagerfeld prominently, the collaboration marked a new level of visibility and fame for the designer. His gessoed pony tail, shades, high-collared white shirts, and skinny black ties became part of an iconography as recognizable, to everyday people, as Mickey Mouse—a comparison that Lagerfeld himself drew when I interviewed him a year later for a profile in this magazine. At the time, we happened to be sitting in a room in his Paris mansion, where the sole décor was a life-size cardboard cutout of Lagerfeld from the H & M marketing campaign.

Subsequent collaborations have not resulted in instant renown for every designer who participates, but they have significantly raised every designer’s profile—sometimes, Schneider told me, to the designer’s chagrin. Rei Kawakubo’s mystique, as the creative director of the avant-garde design label Comme des Garçons, relies in part on her invisibility. When she created an H & M collection, in 2008, she declined to submit to the kind of marketing the brand had deployed for Lagerfeld. Likewise Isabel Marant, who created a popular collection of her French boho-chic line, in 2013. “Isabel is a very private person,” Schneider told me, “but after her collaboration with us she gets stopped all the time on the street by tourists. They want to take selfies with her.”

Rousteing, whose success as creative director of Balmain relies to no small degree on his flair for self-promotion (he has over a million followers on Instagram, where he frequently posts selfies featuring his “besties,” the Kardashians and Jenners), has no such reservations. Like Lagerfeld, his face is featured heavily in promotional billboards, magazine campaigns, and TV commercials, and he has made himself highly available to the press. (Last spring, he flew twenty-six hours round-trip from Paris to Las Vegas to pose with Kendall Jenner for a red-carpet announcement.) And with his army of reality-star friends lending themselves to the advertising campaign, the current collaboration is expected to be one of the most successful since the Lagerfeld.