UPDATE with more information, below.

Condé Nast publishing magnate S.I. Newhouse died today at his home following a long illness, his family confirms. He was 89.

The Newhouse family statement reads: “Today is a day of emotion, of genuine loss, for our family and for Si Newhouse’s extended family at Condé Nast. Si loved Condé Nast. He was proud to publish the finest magazines in the world and to offer exceptional content on every digital platform.”

Newhouse’s death comes just four days after that of another pioneer of magazine publishing, Hugh Hefner, who died Wednesday at 91.

“He instinctively knew that there is no guidebook to being an editor,” said Vanity Fair editor Graydon Carter, “success comes only from confidence and a vision that forms over time. Most important, for an editor to thrive, he or she has to be blessed with a comforting and nurturing proprietor. In this respect, Si had no equal.”

As chairman (and, at his death, chairman emeritus) Newhouse – the full name that he rarely used was Samuel Irving Newhouse Jr., Si more commonly – presided over a stable of magazines that were the very definition of glossy: Vogue, The New Yorker, Glamour, Vanity Fair, Architectural Digest, Details, Self, Wired, Bon Appétit and GQ.

“Si Newhouse was the most extraordinary leader,” Vogue editor in chief (and, since 2013, Condé Nast artistic director) Anna Wintour said today. “Wherever he led, we followed, unquestioningly, simply because he put the most incredible faith in us. Si never looked at data, or statistics, but went with his instincts, and expected us to do the same. He was quick to encourage us to take risks, and effusive in his praise when they paid off. There was nothing showy about the way Si led though. This humble, thoughtful, idiosyncratic man, possibly the least judgmental person I have ever known, preferred family, friends, art, movies, and his beloved pugs over the flashiness of the New York media world, and his personality shaped the entire company; it might have been a huge global entity, yet one felt a deep, personal connection to it, all because of him.”

Newhouse also was co-chairman – with his younger brother Donald, who ran the newspaper side of the empire – of Condé Nasts’s corporate parent, Advance Publications. Condé Nast became known as a kind of velvet coffin, where editors were lavishly compensated and granted extraordinary freedom in developing their titles. The man himself was diminutive of stature, famously introverted and given to informal attire, from his old sweaters to his tennis shoes notwithstanding a family fortune in the billions and one of the world’s great private art collections.

And whether or not he himself paid attention into the ledger-sheet side of the business, Newhouse also had the acumen to bolster the CN corporate staff with a series of increasingly techno-savvy deputies, gradually yielding more and more of his authority to younger protégés attuned to the changes that would upend publishing in general and the magazine industry in particular. The economic upheavals of the last two decades and the emergence of the Internet as disseminator of information and devourer of advertising dollars forced wholesale changes in the business.

Newhouse oversaw the transition to multiple platforms, savvier web sites for his top titles and a ruthless culling of underperformers, including Gourmet, House and Garden, and the short-lived Portfolio. The decisions were his but the news often was delivered by underlings in unceremonious ways, with editors learning of their dismissal while on vacation or through news accounts. Typically, their parachutes were golden.

In a memorial posted this morning on Vanity Fair’s website, Carter wrote that “with the revival of Vanity Fair, in 1983, and the purchase of The New Yorker, in 1985, Si transformed his company into a powerhouse of style and substance. He inherited a carriage-trade house encompassing Vogue, Glamour, House & Garden, and Mademoiselle, and built from there, launching or adding not only Vanity Fair and The New Yorker but Self, GQ, Wired, Details, W, Architectural Digest, Gourmet, and Bon Appétit, among other titles. In 1980, he built out the book side of the family business by purchasing Random House, including Alfred A. Knopf.”

With his passing, Carter writes, “so goes the last of the great visionaries of the magazine business. Indeed, in a career that spanned more than six decades, he placed the Newhouse family name firmly in the pantheon of American publishing, alongside those of Luce, Sulzberger, Graham, and Hearst.”

Newhouse is survived by wife Victoria, two children and a  brother.