In The Crown season 4, Emma Corrin takes on the monumental task of playing Princess Diana, and the actress's portrayal is eerily accurate. Fans had long anticipated Diana's arrival and this messy and highly-publicized period in the royal family's lives beginning when Charles meets the 16-year-old Diana in 1977 and includes their whirlwind courtship, Diana's struggles with depression and bulimia, the birth of their children, and Charles' ongoing relationship with his longtime love Camilla Parker Bowles.

According to an article in the Los Angeles Times, Corrin's uncanny resemblance to Diana initially worked against her. The series' executive producer Benjamin Caron stated, "Normally we don’t go to someone who is almost a lookalike. We find the best actor. But she had both, and that felt a little bit unnerving.” Once Corrin landed the coveted role of Diana, she did extensive research about the woman dubbed the "People's Princess." The resource she found the most helpful was the documentary Diana: In Her Own Words (currently airing on Netflix). The film consists of photos, video footage, and interviews Diana did for Andrew Morton's biography Diana: Her True Story, In Her Own Words, published in 1992.

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The documentary includes pivotal moments in the couple's relationship, also seen in episodes of The Crown, such as Charles and Diana's engagement announcement. Corrin perfectly recreates the moment when a demure Diana affectionately leans her head against her fiance's shoulder. In the interest of accuracy, the actress also nails Diana's sheepish expression during the speech Charles makes when the couple tours Australia and New Zealand. This moment of modesty from the Princess leads to an argument because between the couple because an insecure Charles believes his wife was mocking him behind his back. The Crown does seem to land on the side of Princess Diana as the inured party in the union due in large part to Corrin's excellent performance.

Emma Corrin as Princess Diana in her wedding dress in The Crown

In season 4, Diana goes from a naive girl with big hopes and dreams to a troubled, sick woman plagued by jealousy, and whose commitment to philanthropy is seen by some royal family members, particularly a resentful Charles, as grandstanding and attention-grabbing instead of truly altruistic. And while Morgan takes dramatic license with much of the show's content, he and Corrin were determined to keep Princess Diana's struggle with bulimia as realistic as possible. In Diana: In Her Own Words, she admitted the bulimia started a week into her engagement, and during her honeymoon, Diana was vomiting multiple times a day. On The Crown, while she's living almost in complete isolation ignored by her fiance and dismissed or mocked and insulted by her future in-laws (Princess Margaret played again by Helena Bonham Carter), Diana makes a late-night trip to the kitchen where she binges on an assortment of sweets and then throws up. Corrin told The Wrap:

“From the beginning, when I read the scripts and I realized they were going to allude to her bulimia — I was working with my movement coach at the time, Polly Bennett — and I remember us discussing it and I said, ‘Look, if we’re going to show this, I really want to make sure I do it justice.'”

Other integral components in Corrin's transformation into the Princess of Wales were wardrobe, hair, and makeup: all of which revealed aspects of Diana's personality and served as a road map for her journey from a teenager to a fashion icon. Costume designer Amy Roberts told the NY Post"We started with Diana as a young, casual, not particularly stylish girl, dressing her in scuffed flat shoes, bobbly jumpers [sweaters], casual shirts and jackets,” she said. “Then she moves to the palace where her look becomes more manufactured.” Another signature physical feature of Diana's was her hair, and Corrin wore three wigs, each signifying a different chapter in Diana's life. Both inside and out, Corrin (whose previous acting credits include British TV) personifies the late Princess Diana on The Crown.

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