Lili Elbe was one of the first people to get sex-reassignment surgery. Inside the real story behind The Danish Girl

A movie about a transgender artist couldn’t be timelier in 2015, the year of Caitlyn Jenner and new momentum for transgender rights. But the surprising real story behind The Danish Girl took place a century ago, when Lili Elbe, played by Eddie Redmayne in the movie, became one of the first people to live openly as a transgender woman and to undergo sex-reassignment surgery.

(Spoiler alert: While The Danish Girl is based a novel that fictionalized Elbe’s story, this article reveals some plot points.)

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Named Einar Wegener at birth, Elbe was a prominent Danish landscape painter in the 1920s. Her journey from male to female was kickstarted partly by accident, when her wife, Gerda Wegener, a painter and magazine illustrator played by Alicia Vikander in the film, asked Elbe to sit in for a female model who failed to turn up for a sitting.

At first Elbe resisted, but at her wife’s insistence, she eventually conceded and dressed in the model’s clothes. “I cannot deny, strange as it may sound, that I enjoyed myself in this disguise. I liked the feel of soft women’s clothing,” she wrote in her diary, according to the Telegraph. “I felt very much at home in them from the first moment.”

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The experience awakened something buried inside her, and Elbe decided to continue modeling for her wife using the name Lili. In 1912, the couple moved to Paris, where Elbe was able to live openly as a woman, attending balls and social events while pretending she was Einar’s sister.

Despite the unconventional marriage, Gerda remained supportive of her husband for the next 15 years. “The key to Lili and Gerda’s story was Gerda’s unconditional love for Lili,” The Danish Girl director Tom Hooper tells PEOPLE in the magazine’s new issue. “Theirs was an extraordinary love story. There was no language, no precedent.”

While Elbe felt liberated living as a woman in Paris, something was still missing from her life. According to her diary, all attempts at seeking a medical solution to her depression failed. “I said to myself that as my case has never been known in the history of the medical art, it simply did not exist, it simply could not exist,” she wrote, according to the Telegraph.

Unable to live in peace with her biological body, “Lili had been considering suicide for some time before her transition,” Danish Girl screenwriter Lucinda Coxon tells PEOPLE. But instead, she decided to undergo a series of groundbreaking procedures at the Dresden clinic of Kurt Warnekros in Germany. While the details of the operations are unknown, Elbe’s testicles and penis were removed and the ovaries of a young woman was grafted into her body, according to the Telegraph. She took the surname Elbe in honor of the river that runs through Dresden.

“When I think how courageous you would have to be… No one had heard of transgender at the time – then to go into that surgery. There was no penicillin, [remedial] pain relievers,” says Coxon.

Elbe and Gerda divorced amicably in 1930 with an official annulment from the Danish king. Despite the friendly split, and receiving support from her brother and sister, Elbe still felt incomplete. She had stopped painting after her surgery, explaining in her diary, “It is not with my brain, not with my eyes, not with my hands that I want to be creative, but with my heart and with my blood, she wrote, the Telegraph reports. “The fervent longing in my woman s life is to become the mother of a child.”

In the hopes of one day carrying a child, she went through another round of operations in September of 1931, this time with the goal of successfully transplanting a womb into her body. Unfortunately, ciclosporin, a drug doctors use to prevent the body from rejecting transplanted organs, would not be used successfully for another 50 years. Elbe died as a result of the procedure on September 13, 1931.