In life, Sumner Redstone expended considerable energy to promote his legend as a daring and cutthroat media mogul who amassed one of the world’s largest collections of TV and film assets.

After his death at the age of 97 on Aug. 11, it became clear that Redstone’s greatest living legacy was never destined to be Paramount Pictures, or MTV or CBS or Showtime or Nickelodeon or any of the other prizes he claimed in more than a half-century of aggressive dealmaking. At a moment of massive transition for the entertainment industry, Redstone’s most significant bequest is to have laid the foundation for the first woman — his daughter, Shari Redstone — to wield power as a true boss and owner in 21st-century Hollywood.

“Perhaps his most remarkable achievement was producing a person even tougher than himself in Shari,” says Erik Gordon, professor at University of Michigan’s Ross School of Business.

Redstone had complicated relationships with both of his children, son Brent and daughter Shari. The billionaire’s family battles frequently played out on the business pages of major newspapers as the outcomes had implications for the Redstone empire. After all, Sumner Redstone was already 64 in 1987 when he expanded from the exhibition business to making multibillion-dollar bets on the entertainment companies that led him to coin the phrase “Content is king.”

Shari Redstone worked for years at the family’s National Amusements holding company, where she proved to be an innovator in running the movie theaters. On her watch, National Amusements’ were among the first theaters to offer expanded luxury touches like food and drink service.

Sumner Redstone’s iron-clad control of voting rights in Viacom and CBS Corp. made the question of succession important to shareholders after he became an octogenarian. Shari Redstone faced down industry doubts and her father’s public statements that he did not see her as capable of taking over the empire. In 2014, as it was later revealed, Sumner tried to buy out Shari’s 20% stake in National Amusements for $1 billion and force her to give up her right to lead his companies after his death.

Within a year of that offer, Sumner Redstone’s life changed dramatically. In October 2015, Shari Redstone took action to straighten out the business affairs of her father, whose appetite for female companions was well known. Shari Redstone ejected two former girlfriends of her father’s from his Beverly Park home and took a firm hand in guiding his health care decisions as he became more dependent on caregivers.

From there, Shari went on a quest to revamp the leadership of Viacom and CBS and to exert her influence over the governance of the Redstone family trust that is the inheritor of Sumner Redstone’s holdings. Methodically, she flexed her legal and corporate muscle to remove former Viacom CEO Philippe Dauman, Sumner’s longtime lawyer, as leader of the struggling company and as key figure in the Redstone trust.

Waging the kind of campaign her father employed to land Viacom and Paramount Pictures in the 1980s and ’90s, Shari moved on to revamp the boards of Viacom and CBS, including ousting longtime CBS chief Leslie Moonves. The last major piece fell into place in December when she realized her desire to reunite Viacom and CBS formally under one roof — some 14 years after they were split into separate companies by her father in frustration over Viacom’s sagging stock price.

Shari Redstone still has plenty of detractors. She may well face challenges from within her extended family to aspects of her father’s estate and how she handled the revamp of the family trust amid a flurry of litigation in 2016. But after the past five years, few would doubt that she has the same kind of Boston-bred toughness that marked Sumner Redstone in his heyday.

“Shari had to wrestle with her own father and doubly prove herself before industry players stopped looking at her as Sumner’s daughter and took her seriously,” Gordon says.

As a woman, Shari Redstone is a trailblazer. As a media magnate, she is forced to grapple with a dilemma her father never faced — namely, whether even the newly merged ViacomCBS is too small to compete in the increasingly global village of entertainment. Speculation about her willingness to sell the crown jewels began as soon as word of Sumner’s death hit the news cycle.

Friends of Shari Redstone say that her track record to date speaks volumes about her skill and her dedication to preserving and protecting all that her father built.

“I have been so impressed by the way Shari worked her way through the myriad of issues she has faced over the past several years. She set a plan, stuck to it and came out exactly where she wanted to,” says Tony Vinciquerra, chairman-CEO of Sony Pictures Entertainment. “If you think of all the constituencies she was facing, it is remarkable. Shari is the real deal. Above all, she did it with grace, patience and a passion to see the businesses her father created get to the next level.”