Sumner Redstone, a combative and daring dealmaker who in his 60s turned his family’s movie theater chain into one of the world’s largest media empires, with holdings that included Paramount Pictures film studios, CBS, MTV and the publishing house Simon & Schuster, died Aug. 11 at his home in Los Angeles. He was 97.

His media holding company, National Amusements, announced the death in a statement but did not provide additional details. A spokeswoman, Sara Evans, did not specify the cause but said it was not related to the novel coronavirus.

In recent years, as the mogul’s mental and physical decline became increasingly apparent, legal and public-relations battles erupted among his presumed successors, members of the family and an array of other hangers-on. All had a stake in inheriting chunks of his $40 billion business empire, his personal fortune or both.

The trouble accelerated as Mr. Redstone’s last will and testament underwent revisions and as he seemed to decree management shufflings and firings that hurt those who thought they had secured his favor.

Among the primary combatants were his daughter, Shari Redstone, a lawyer from whom he was once estranged but who gradually attained a large stake in his businesses; and a granddaughter, Keryn Redstone, who accused her aunt Shari of isolating and manipulating the media chieftain in his mental twilight.

Other players included Philippe P. Dauman, a longtime confidant of Mr. Redstone and a nemesis of Shari Redstone, who was unexpectedly ousted as chief executive of Viacom, the media conglomerate controlled by Sumner Redstone; and Manuela Herzer, Mr. Redstone’s former girlfriend, who served as his live-in health aide until she was suddenly ejected from his will and his residence. Herzer brought a lawsuit that raised serious questions about Mr. Redstone’s state of mind and that revealed embarrassing details of his alleged sexual appetites.

Ultimately, many business observers blamed the monarchical Mr. Redstone for allowing tensions to fester because of his refusal for so long to relinquish control. He favored the motto “live forever, work forever” and once told an interviewer that dying was “not on my agenda.”

Amid lawsuits and shareholder challenges regarding his ability to run a corporate behemoth in his 90s, he resigned as executive chairman of CBS in February 2016 and was replaced by CBS chief executive Leslie Moonves, who then resigned in September 2018 after several women accused him of sexual assault. Mr. Redstone’s successor at Viacom was Robert M. Bakish.

In January 2019, Mr. Redstone reached a settlement with Herzer. Later that year, Shari Redstone proved as formidable as her father, when she emerged victorious in a negotiation to merge CBS and Viacom — which had split in 2006 — into a new entity called ViacomCBS, over which she would preside as chairwoman.

The merger, Shari Redstone argued, was the best way for the media companies controlled by the Redstones through their private theater chain, National Amusements, to compete with older and rising entertainment giants, from Walt Disney to Netflix.

A grit forged in fire

Mr. Redstone, raised in a Boston tenement with a shared bathroom, was a studious overachiever who served as a code breaker during World War II and graduated from Harvard Law School. Starting in 1954, he abandoned a lucrative law practice in Washington with the aim of transforming his family’s modest drive-in movie business into a national enterprise of multiplex theaters.

In a hostile takeover in 1987, he gained control of the media conglomerate Viacom, and a few years later he bought Paramount and CBS. The deals catapulted him to the front rank of entertainment giants, with the ownership of such properties as Showtime, Comedy Central, Nickelodeon and BET. He also once controlled the video-rental company Blockbuster.

“Entertainment and information started to merge together,” said Gary R. Edgerton, a media historian at Butler University in Indianapolis. Mr. Redstone “rapidly recognized the changes that were occurring,” Edgerton said, and he had a gift for “recognizing the value of properties early on and making the most of them.”

The Redstone holdings ranked alongside those of Walt Disney Co., Time Warner and News Corp. in scale and profitability, and Mr. Redstone had the power and presence of other media kingpins such as Rupert Murdoch and Ted Turner. In 2019, Forbes magazine estimated his net worth at $4.5 billion.

Fiercely protective of his business interests, Mr. Redstone let Paramount’s deal with Tom Cruise’s production company lapse in 2006, chiding one of the world’s biggest movie stars for offbeat public behavior that he thought was hurting the company at the box office.

“We don’t think that someone who effectuates creative suicide, and costs the company revenue should be on the lot,” Mr. Redstone told the Wall Street Journal at the time.

A chastened Cruise showed up for Mr. Redstone’s star-studded 90th birthday party in 2013 along with former vice president Al Gore, financier and “junk bond king” Michael Milken and assorted Hollywood luminaries. Tony Bennett crooned to Mr. Redstone, crediting him with helping revive the singer’s career by giving him a presence on MTV in the 1990s.

Not everyone was so enamored of Mr. Redstone, who was known to be hard-driving and litigious. “Viacom is me,” he declared, and he ran through a succession of chief executives and got into public feuds with his children over the future of the company.

Much of the lore surrounding Mr. Redstone’s grit involved a March 1979 fire he survived while staying at Boston’s Copley Plaza Hotel. He climbed out a window and crouched on the third-floor ledge, clinging to the building with a hand still caught in the blaze, which was set by a disgruntled ex-employee of the hotel.

“My legs had been burned to the arteries, now my arm was charring,” he recalled in “A Passion to Win,” his 2001 autobiography written with Peter Knobler. “The pain was excruciating but I refused to let go. That way was death.”

A firefighter finally reached Mr. Redstone and pulled him to safety. Surgeons worked on him for 60 hours, treating third-degree burns that covered half his body. Despite months of care and bone and skin grafts, Mr. Redstone was left with an arm and hand permanently damaged.

“The most exciting things that have happened to me in my professional life have occurred after the fire but not because of it,” he wrote. “It doesn’t take near death to bring you to life. Life begins whenever you want it to begin.”

'I had to be the best'

Sumner Murray Rothstein was born in Boston on May 27, 1923. His father, a linoleum salesman, later owned a restaurant, nightclubs and drive-in theaters. In part because of anti-Semitism, he changed the family’s name to Redstone.

Mr. Redstone attributed his intense manner to his mother, who often turned back the hands of the clock to extend her son’s piano practice. He ranked at the top of his class at the Boston Latin School, a public school known for its rigor.

“The 10 cents I spent every day on the round-trip streetcar fare was a significant expense for my family,” he later recalled. “I had to justify that expense. I had to be the best. That meant no slips, no lapses, no room for error.”

He completed his undergraduate course work at Harvard in three years and, during World War II, was selected for a secret program that broke Japanese military and diplomatic codes.

After graduation from Harvard Law School in 1947, Mr. Redstone came to Washington, where he later served as a special assistant to U.S. Attorney General Tom C. Clark before becoming a partner in a private law practice in the city.

In 1954, taking a pay cut from $100,000 a year to $5,000, Mr. Redstone joined the family business, a 12-theater drive-in chain then called Northeast Theater Corp. Four years later, he brought an antitrust lawsuit that charged major movie exhibitors and distributors with discriminating against drive-ins by denying them the same access to first-run movies as traditional theaters.

The case was settled out of court, and Mr. Redstone said he won “essentially everything we sued for.”

He became chief executive of the renamed National Amusements in 1967. He also bought out most of the shares of a younger brother, Edward, who later sued Mr. Redstone and their father, saying they had squeezed him out of the business. A financial settlement was reached, but the family remained divided for years.

Mr. Redstone, meanwhile, became an early force in building large indoor theaters — multiplexes — far outside city centers. His Dedham, Mass.-based company owned more than 120 theaters by the mid-1970s. He also began to invest in movie companies and to claim millions of dollars in profits when they were taken over by conglomerates.

In the 1980s, as Mr. Redstone watched cable outlets and VCR tapes eat away at movie attendance, he set his sights on Viacom, a syndication company that owned MTV and Showtime, as well as other broadcast and cable television operations. He bought the conglomerate for $3.4 billion in 1987 after a bidding war with a Viacom management group.

Some analysts thought Mr. Redstone had vastly overpaid for Viacom and would sell off many of its assets, such as MTV and Nickelodeon. But he kept the company together, and its revenue exploded.

“People were saying MTV was a fad,” he told business channel CNBC in 2012. “That fad now reaches just a billion people. People were saying that Nickelodeon would never work because it was a kids’ channel. . . . Today, Nickelodeon’s the number one channel on television.”

In the early 1990s, Mr. Redstone arranged a deal with Paramount chief executive Martin Davis to buy the venerable film studio. But when it was announced, a bidding battle ensued with a group led by then-QVC chief Barry Diller, who was backed by other powerful media players.

Mr. Redstone, who won the war for $10 billion, came to call the saga, which entailed lawsuits and private investigators, the “deal from hell.”

After selling off some of Paramount’s holdings, including the New York Knicks and New York Rangers, Mr. Redstone expanded the company’s cable TV presence. He was able to package Viacom offerings, such as the Nickelodeon series “Rugrats,” as Paramount films, home videos and book spinoffs through Simon & Schuster, another of the company’s properties. Paramount also had a succession of major box-office hits with “Forrest Gump,” “Braveheart” and “Titanic,” the last a co-production with Twentieth Century Fox.

Mr. Redstone’s biggest acquisition took place in 2000, when he finalized the $37 billion purchase of CBS — which had once been Viacom’s parent company. The companies split again in 2006.

“It’s very hard for one guy and his team to pay attention to a lot of businesses,” said Ava Seave, a co-author of the 2009 book “The Curse of the Mogul: What’s Wrong With the World’s Leading Media Companies.” “The company was really addicted to growth.”

Another concern was Mr. Redstone’s unwillingness to name a successor when he turned 90. His relationship with his children, Brent and Shari Redstone, grew tumultuous and at times litigious, as they quarreled over their roles in their father’s business empire.

They were Mr. Redstone’s children with his first wife, Phyllis Raphael, whom he married in 1947 and divorced 52 years later. He married Paula Fortunato, a schoolteacher 39 years his junior, in 2003. The marriage was short-lived. He had a string of live-in, much younger girlfriends who acted as gatekeepers, until they became persona non grata on the mogul’s whim. In addition to his children, survivors include five grandchildren and several great-grandchildren.

For all his formidable reputation in the media, Mr. Redstone was thin-skinned about how he was portrayed in print. He talked frequently about his exercise habits, meticulous diet and favorite antioxidants, which he said enabled him to maintain vigor at all hours.

Jim Geswelli, whose wife is Fortunato’s sister, visited Mr. Redstone’s home in California and told Vanity Fair in 2006 how demanding Mr. Redstone could be.

“At 4 o’clock in the morning, he gets on the intercom system and starts going, ‘Coffee, coffee, coffee,’ ” Geswelli said. “Over time, you know, he gets louder and louder, and finally, by 5, someone goes down to have coffee with him.”

Marino-Nachison is a former Washington Post staff writer.