Before Meghan Markle or even Kate Middleton, it was Princess Diana of Wales who was setting beauty trends across the globe. And it turns out her signature look was a spontaneous choice made by the royal.

Sam McKnight, who once served as Diana’s stylist, revealed in his new book, titled “Hair by Sam McKnight,” that her iconic haircut first made its grand debut in a 1990 magazine cover. And while that image of the late princess has since been immortalized, McKnight insisted the hairdo in the photo wasn’t actually real.

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“I made her hair look short in the tiara for the shoot and she decided she liked it,” wrote McKnight, as reported by Us Weekly. “As she was leaving, Diana asked what would I do to her hair if I had free reign… I suggested cutting it short and she, to my surprise, agreed, and we did it there and then."

McKnight added he used “hair grips” to tuck Diana’s shoulder-length tresses under the tiara, a style that would soon become one of the most sought after looks during her lifetime.

Perhaps Diana was looking for something to lift her spirits at the time. Just two years later, journalist Andrew Morton penned the 1992 biography “Diana: Her Story,” which was based on the secretly recorded conversations between the princess and her friend, James Colthurst, before her divorce from Prince Charles in 1996. The book was published with Diana’s consent.

“It was a sign at that time [of] this desperation to get the [real] story out,” Morton told Fox News in July 2017. “I asked her [why] and she just felt the public didn’t really know who she was. They were responding to a two-dimensional image. This kind of media cut-out… she felt like she was enduring a lonely miserable life inside the palace and outside, she was adored… It was incredibly frustrating as far as she was concerned because everyone still believed in the fairy tale. And she knew it was a nightmare.”

Diana had long suspected her husband Prince Charles was having an ongoing affair with his ex-girlfriend Camilla Parker Bowles, Morton said.

The mother of two died in 1997 from a car crash in Paris at age 36.

Charles married Camilla, now Duchess of Cornwall, in 2005.