Father and daughter also joined forces to fight the Viacom board, which challenged Mr. Redstone’s mental competency in court in 2016.
Mr. Redstone’s death has bolstered his daughter’s influence over National Amusements. His voting stock in the company — an 80 percent share — will transfer to a seven-member trust that includes Ms. Redstone and her son, Tyler Korff, along with Jill Krutick, a longtime family friend, and four lawyers with ties to the Redstones. Ms. Redstone holds the remaining 20 percent of National Amusements through a separate trust.
The main trust owns controlling shares in National Amusements, which in turn controls about 80 percent of the voting rights in ViacomCBS, the company that resulted from a 2019 merger led by Ms. Redstone.
The structure of the empire built by Mr. Redstone is complex — but Ms. Redstone is at the top.
Father-daughter duos are rare in the upper echelons of corporate America, and combative ones even more so, said Rita McGrath, a professor at Columbia Business School and the head of its Women in Leadership program. She noted that Hugh Hefner had a long working relationship with his daughter, Christie Hefner, who was chief executive of Playboy Enterprises for 20 years; and that Abigail Johnson took over Fidelity Investments in 2014, after her father, Edward Johnson III, ran the business for nearly four decades. The Redstones operated more like a wolf pack, Ms. McGrath said.
“You can only have so many alphas in one room,” she said.
Ms. McGrath pointed to Ms. Redstone’s skill in assembling allies under pressure, adding, “She was actually incredibly effective at pulling together a coalition of very smart people who were willing to challenge Sumner, who were basically betting their careers that she’d be able to come out on top. Forty years ago, you wouldn’t be seeing people taking that kind of bet on a woman.”
In May 2019, Ms. Redstone made an appearance at a lavish fete at the Plaza hotel thrown by CBS to court business during its annual presentation to advertisers. A receiving line of network executives and on-air stars lined up to greet her as trays of mini cheeseburgers and pinot noir circulated.
It was her party.