Princess Diana‘s romance withPrince Charlesmay have seemed like a fairy tale to outsiders, but she felt like a princess trapped in a tower.

Diana’s unhappiness in the marriage was growing as Charles carried on a longtime affair with mistress Camilla Parker Bowles, and she decided to secretly tell her story through a biography.

“It explained Diana’s feelings, her sense of isolation, her sense of being a prisoner,” Andrew Morton, author ofDiana: Her True Story, says. “Once that leached into the popular imagination and people got to understand who she was as a three-dimensional character, then people responded to her.”

He added, “And you could see that people wanted the Diana monarchy, one that was more approachable, a bit looser. A little bit more empathetic to their own issues and problems.”

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Betrothed

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Sant Jordi’s Day 2013 in Barcelona

Morton has since published several biographies on other famous figures, including royals such as Wallis Simpson (the book he was promoting when he collapsed) andPrince William, as well as celebrities likeTom Cruiseand Monica Lewinsky. His latest book is a biography ofMeghan MarkletitledMeghan: A Hollywood Princess.

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Ahead of the publication ofMeghan: A Hollywood Princess, Mortonspoke to PEOPLE about Meghan and Harryand how life in the royal spotlight has been difficult for Harry over the years.

“Being a royal has been a romantic curse for him,” Morton said.

This week’s issue of PEOPLE celebrates how the women in the Windsor family, fromQueen ElizabethtoPrincess DianaandKate MiddletontoMeghan Markle, have each helped usher new ways forward.

source: people.com