Chairman Emeritus of Condé Nast Samuel Irving “Si” Newhouse, Jr, died on Sunday at the age of 89. A spokesperson for his family said he succumbed to a long illness, reported Vogue, one of the magazines that runs under Condé Nast Publications.

“Si Newhouse was the most extraordinary leader,” said Anna Wintour, Condé Nast artistic director and editor-in-chief of Vogue. “This humble, thoughtful, highly idiosyncratic man, quite possibly the least judgmental person I’ve ever known, preferred family, friends, art, movies, and his beloved pugs over the flashiness of the New York media world. His personality shaped the entire company.”

Newhouse and his brother Donald owned Advance Publications, which was was founded by their father in 1922. The companies assets include Condé Nast, dozens of newspapers across the United States and a controlling stake in Discovery Communications.

Other publications run by Condé Nast include Vanity Fair and The New Yorker.