On Sharon Tate’s last day alive, the pregnant actress argued with her husband and ate lunch by the pool with her friends. She took a nap and may have gone out to dinner. By all accounts, she was home before 10 p.m.

Then Charles Manson’s followers showed up.

“At that point in her life, she was completely and 100 percent ready to settle down,” said Alisa Statman, the author of “Restless Souls,” a book about the Tate family. “All she wanted was a steady home where she could actually get her mail sent to, and she wanted a family.”

Neither of those wishes materialized for Tate, who was brutally killed on Aug. 9, 1969, by members of the Manson “family” — causing many people in Hollywood to fear for their own lives and casting a shadow over the counterculture that had fueled Manson’s cult.

After his lengthy trial and conviction, Manson became a constant and morbid presence in pop culture. (The Washington Post)

Tate, 26, was eight months pregnant and fed up with what she felt was mistreatment by her husband, filmmaker Roman Polanski, whom she had married the previous year. If he didn’t change his behavior in the first two weeks after the baby was born, Statman said, Tate intended to divorce him.

(In 1977, Polanski pleaded guilty to having sex with a 13-year-old girl and fled the United States after serving 42 days in prison. He has evaded efforts to extradite him back to the United States ever since. )

The newlyweds traveled that summer to Europe, where Tate filmed “The Thirteen Chairs” and Polanski scouted out movie locations. Tate returned home alone to Benedict Canyon, Calif., on July 17, 1969, after Polanski insisted he couldn’t yet leave London.

His friends Wojciech Frykowski and coffee heiress Abigail Folger, who had been housesitting, were still at the couple’s rented mansion on Cielo Drive in August.

Around 11 a.m. on Aug. 8, 1969, Statman said, Polanski called Tate and the couple argued over Polanski again delaying his trip home. Tate was planning a birthday party for him 10 days later, and she told him she would split from him if he hadn’t returned by then.

Sharing lunch by the pool, Tate complained about Polanski to her friends, actresses Joanna Pettet and Barbara Lewis, and talked about how elated she was to have a child. Frykowski and Folger joined the group around 3 p.m., Statman said, before Tate went inside to take a nap.

Celebrity hair stylist Jay Sebring, Tate’s ex-fiance, came to the house that evening around 6. The son of a local bicycle shop owner also stopped by to exchange a bike that Folger had bought. He was the last person to see Tate, Frykowski, Folger and Sebring alive.

The group may have later gone to the well-known Los Angeles restaurant El Coyote, Statman said, although there is some question about that. In any case, the group was home by 10 p.m., when Folger called her mother to talk about her plan to fly to San Francisco the next day to celebrate her birthday.

It was “a night so quiet you could almost hear the sound of ice rattling in cocktail shakers in the homes way down the canyon,” United Press International reported 10 years later, partly quoting the book “Helter Skelter” by Vincent Bugliosi, who prosecuted Manson.

But sometime in the early morning, four of Manson’s followers climbed over the driveway gate and launched a savage attack. First they saw Steven Parent, who had come to try to sell a clock radio to the estate’s caretaker, and they shot him. Then they went inside and killed the four others.

Tate was stabbed 16 times, Statman said. The killers — Charles “Tex” Watson, Susan Atkins, Patricia Krenwinkel and Linda Kasabian — painted the word “PIG” on the home’s front door with Tate’s blood.

Although other celebrities were terrified that their own deaths might follow, Statman said most people initially shrugged off the killings.

“The rest of the country was like, ‘Well, it’s a movie star. You know how they live,’ ” Statman said. “When the murders happened the next night, that’s when the fear swept across the United States.”

Manson took several of his followers that night to the Los Angeles home of grocery store executive Leno LaBianca and his wife, Rosemary LaBianca, where the cult members killed the couple and wrote “Rise” and “Death to pigs” on the wall with blood. They also wrote “Healter Skelter” on the refrigerator door — a misspelled reference to a Beatles song that Manson thought alluded to a coming race war.

The Tate-LaBianca murders shifted how some Americans viewed the counterculture that Manson had exploited to attract troubled young people to his desert commune. The Woodstock music festival, which took place the following week, further polarized the divide between those who embraced the hippie ethos and those who were repulsed by it.

Tate’s family, meanwhile, was critical in advocating victims’ rights in California. Her mother, Doris Tate, addressed Watson, one of the killers, at his parole hearing in 1984 — the first impact statement to be given in the state. She also advocated the Victims’ Bill of Rights, a 1982 California law that codified victims’ right to provide impact statements.

“This family took the most heinous circumstances on the planet and turned it into a positive," Statman said. “The Tate family proved that in the most adverse circumstances, you don’t have to turn out like these killers — ever.”

Correction: A previous version of this story misstated Roman Polanski’s location when Sharon Tate left Europe. He was in London. The story also misidentified Barbara Lewis’s profession She was an actress.

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