Editor’s Note: To learn more about Marilyn Monroe’s life and legacy, check out the new CNN Original Series “Reframed: Marilyn Monroe” premiering Sunday, January 16, at 9 p.m. ET with back-to back episodes.

CNN  — 

Marilyn Monroe went down in the history books as a blonde bombshell who many wrote off as just a pretty face. But Monroe was a trailblazer.

When she was dismissed as a replaceable actress, Monroe knew her worth and boldly advocated for herself.

“She was finding her power,” said photographer Nancy Lee Andrews. “Becoming Marilyn is not a tragedy. It’s a triumph.”

When you examine this iconic movie star off-camera, the depth of her life comes into full picture. Here’s a behind-the-scenes look at how Monroe strategically navigated her career.

Not just another dumb blonde

One of Monroe’s early hits was the musical comedy “Gentlemen Prefer Blondes.” She played a dumb blonde gold digger named Lorelei, a showgirl sailing to France to marry a wealthy man.

“I can be smart when it’s important. But most men don’t like it,” she says in the film, a line Monroe insisted on using.

Monroe had no control over casting while under contract with 20th Century Fox. The studios had a stranglehold on the industry. This was also a time when very few women were producing, writing or directing. In the mid-1950s, only 5% of US movie writers were female, according to a study by Luis Amaral of Northwestern University.

Despite the lack of female representation, Monroe found power by adding complexity to these simple characters.

“It was crucial in the evolution of Marilyn’s career and star persona because Lori is the dumb blonde who’s not as dumb as you think she is,” said Sarah Churchwell, a professor of American literature at the University of London.

Monroe played into assumptions to catapult herself into stardom.

“If you are able to not only be in on the joke but to control it, that to me is the mark of a genius,” said actress Amber Tamblyn.

Finding her power and fighting for her worth

Monroe starred in several big hits in 1953, including “How to Marry a Millionaire,” where again she played a dumb blonde. The movie earned Fox $15 million, equivalent to $150 million today.

After being asked to play another pretty one-note leading role in the musical comedy, “The Girl in Pink Tights,” Monroe was fed up. She literally labeled it “trash” and handed it back to the head of the studio, Darryl Zanuck, according to biographer Cindy De La Hoz-Sipala.

She also learned that her costar in the film, Frank Sinatra, would earn $5,000 a week, while she made only $1,500, according to The Marilyn Monroe Collection.

“She was the main attraction,” said actress Mira Sorvino. “I mean, she was the reason that people flocked to the theater. So, it was insane that she wasn’t given a much more powerful position in terms of salary.”

Monroe refused the role until her pay and conditions were improved.

“For anyone who thinks Monroe was a perpetual victim, she walked off the set of ‘Pink Tights.’ Enough said,” said Molly Haskell, author and film critic.

The film was never made, and the studio changed Monroe’s contract, giving her a raise for future roles.

Monroe’s David versus Goliath gamble

In 1954, Monroe filmed the most famous moment of her career: when her dress blows up over a subway grate. The scene is featured in “The Seven Year Itch,” which was a huge hit at the box office.

She was at the pinnacle of her success but was still being typecast. So, she left Hollywood.

Breaking her contract with Fox, she went to New York and launched her own film company, Marilyn Monroe Productions. She also took classes at the Actors Studio. This was all in an effort, as she said, to be seen as a “serious actress.”

Within a year, Fox conceded and offered Monroe a new contract – giving her a higher salary, director approval and the freedom to make films through her own production company.

“She got everything she wanted, everything, which was unheard of in 1955,” said Amy Greene, Monroe’s friend, who was with her when she received the news.

“She was whip smart, witty, ambitious, strategic and above all, incredibly courageous,” said Sam Starbuck, executive producer of “Reframed: Marilyn Monroe.” “She knew her worth and she refused to be dominated by the male studio bosses in Hollywood. She challenged the status quo, turning the tables on them time and time again, and winning.”

Proving her acting chops

Monroe’s first film under her new contract was “Bus Stop.” This was her opportunity to show off her acting chops.

She played a failed musician named Chérie, who aspired to be a big star. Monroe insisted on ghostly makeup because she believed this character never got out in the sunlight. She also perfected an Ozark accent for the role.

“We can see that Marilyn Monroe’s physicality is being treated differently from earlier movies,” said Jeanine Basinger, a professor in film studies at Wesleyan University. “There’s a different quality to it. It’s more realistic. It’s less voyeuristic.”

Critics praised Monroe’s performance.

“A lot of people said that she really deserved an Academy Award nomination for that role,” said film critic Christina Newland.

Monroe creates a film with her own production company

Monroe’s next move was to produce the film, “The Prince and the Showgirl” with her production company.

“‘The Prince and the Showgirl’ was going to finally demonstrate everything that she had been fighting for a decade, that she was going to get all of that credibility that she wanted,” said Churchwell.

Marilyn played Elsie, an American showgirl, who falls for a European prince, played by Laurence Olivier. There were challenges during the filming, like Monroe’s tardiness, but in front of the camera, she shined.

“People who worked with her spoke about these smart notes she would give after watching the [footage], where she said very specific things that she was not happy with and why,” said Alicia Malone, host on Turner Classic Movies. “They were emblematic of a woman who knew her craft and knew exactly what she wanted and exactly what she needed.”

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