Si Newhouse Jr., whose father founded a media behemoth that eventually fell under his purview, died Sunday at his home after a long illness, a family spokesperson confirmed to Vogue. He was 89. Newhouse, along with his brother Donald, owned Advance Publications, which included the Conde Nast empire, more than two dozen newspapers, the Parade magazine insert, and a 25% stake in Discovery Communications, per Variety. Newhouse oversaw the Conde Nast sector, whose brands included such esteemed publications as the New Yorker, Vogue, and Vanity Fair, and which helped the Newhouse family amass a fortune said to be more than $10 billion by the time the new millennium came around, the New York Times notes; Variety reports that as of 2015, each brother was worth about $8.3 billion, per Forbes estimates.
Newhouse's father, Samuel Newhouse Sr.—the younger Newhouse's nickname "Si" stood for Solomon Isidore, though he also was known as Samuel Irving—had launched a newspaper business after starting out as a New Jersey copyboy. While Donald eventually took on the newspapers, Si gravitated toward Conde Nast, earning a rep for showering his editors with hefty expense accounts and letting them "run free," per the Times. Although Newhouse himself was a "shy man" and "painfully awkward," he managed iconic editors, including Vogue's Anna Wintour and Vanity Fair's Tina Brown. "Si Newhouse was the most extraordinary leader," says Wintour. "Wherever he led, I followed, unquestioningly, simply because he put as much faith in me as I had in him." Newhouse is survived by his wife, Victoria, his brother, two children, five grandchildren, and three great-grandchildren.