She left life as melodramatically as she lived it, leaving behind speculation that she had committed suicide and sparking numerous conspiracy theories that she might have been murdered.
That was only the beginning of a dazzling afterlife, where the doomed, vulnerable and voluptuous screen siren would transcend Hollywood and rise to the status of icon, where everyone would relate to her on a first-name basis.
Only Elvis outranks her.
Marilyn has been immortalized in silk screen by Andy Warhol, commemorated in a U.S. postage stamp and feted by Elton John in his song "Candle in the Wind."
There have been numerous biographies, a Barbie doll and movies about her life, including "My Week With Marilyn," in which she was played by Michelle Williams. The NBC TV show "Smash" is about attempts to put on a Marilyn-based musical on Broadway.
As expected, the 50th anniversary of her death brings forth an avalanche of fiction and non-fiction books, some that re-imagine her life, others that analyze specific parts of it. And, of course, there will be photos -- some repackaged, others "never before seen."
Last year, Forbes magazine ranked Monroe third in their list of top-earning dead celebrities, with $27 million in sales.
Warhol was a big fan. In 2010, the Andy Warhol Museum hosted the traveling exhibit "Marilyn Monroe: Life as a Legend," which displayed her image through more than 300 photographs, paintings, works on paper and in print. Warhol collected more than 100 photographs of Monroe, which are part of the Warhol's permanent collection.
"I think that she had the perfect combination of beauty, sex appeal and allure, coupled with a fragility, a sad story and a classic American story of overcoming obstacles to succeed," Warhol director Eric Shiner says. "That really allowed the American public to both emulate her and also connect with her. ... Warhol was no different. He'd been a fan since her career took off."
What enthralls us about her? Her Dickensian childhood, during which her mentally ill mother consigned her to a series of foster homes? Her rumoured dalliances with President John F. Kennedy and his brother, attorney general Robert Kennedy, and Frank Sinatra? Her wiggle? Her giggle?
"I think people are forever fascinated by Marilyn," says Gwen Flamberg, beauty director of US Weekly. "I think it goes beyond just the way that she looked. I think Marilyn stands for this timeless glamour that everyone wants to emulate. There was something about Marilyn that was innocent and naive, and that was something that draws people to her and her look."
Many have emulated Monroe's cotton-candy blonde hair and abundant curves: Jayne Mansfield, Madonna, Anna Nicole Smith, Blake Lively, Christina Aguilera, Lady Gaga and Charlize Theron, who recently appeared with a computer-generated Marilyn in a commercial for J'Adore perfume. But Monroe didn't project the chilly remove of most sexpots.
"Marilyn lived in a time when stars weren't as accessible as they are now," Flamberg says. "I think that's part of the mystique. You couldn't tweet to Marilyn Monroe. What you saw on the screen is what you believed. Marilyn was looking for love. It's very evident when you see her onscreen."
In 2010, a set of three of her chest X-rays from a 1954 hospital visit sold for $45,000 at auction. Last year, the white "subway dress" that she wore in "The Seven Year Itch" sold at auction for $4.6 million, plus fees, making it the most expensive dress in history. In the new book, "Marilyn: The Passion and the Paradox," author Lois Banner speculates that Monroe was bisexual.
Monroe exploded on to the screen during a time when the country's attitudes toward sex were evolving, says Brenda Fiala, a senior vice president of strategy in the New York office of Blast Radius, a digital ad agency.
Fiala has conducted research about the concepts of physical beauty in cultures around the world.
"There are many who have modeled themselves after her from a public-persona point of view," Fiala says. She cites "her tremendous knack for drama offstage, the unusual circumstances around her passing, all make her more iconic and freeze her in our minds. There were lots of women who were voluptuous and sexy. But Elizabeth Taylor aged, and we aged with her."
Last year, Authentic Brand Management bought the rights to Monroe's estate. They've also partnered with most of Monroe's principal photographers. CEO James Salter says they plan to trim the junky merchandise and take the Monroe brand upscale by licensing clothing, jewelry and makeup.
"We've really gone from 300 licences around the world to 130," Salter says. "We've spent a lot of time weeding out the good ones (from) the bad ones."
