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Denmark's crown Prince Frederik should never have married Australian-born Princess Mary and instead stayed with a former flame, the author of a sensational new book on the Danish royal family says.
Veteran royal reporter turned author, Trine Villemann, says the fairytale marriage between Frederik and Mary has come under strain as both try to cope with pressures they face as royals and parents of two young children.
She believes Frederik is not confident in his role as crown prince, does not want to become king, and would have been better off had he married "the true love of his life", former model Katja Storkholm, when they got secretly engaged in 1995.
Villemann examines the royal marriage in her new book, Copenhagen 1015 K, which will be published in Denmark tomorrow.
Villemann said Mary was finding it difficult to deal with Frederik's "dysfunctional" family and was an isolated figure struggling to cope with her husband's regular visits to ex-girlfriends.
She said when Frederik was with Storkholm she helped him be more confident. But his mother, Queen Margrethe, refused to allow them to marry.
"In the Danish royal family there's this tradition of you get your spouse from abroad, you don't marry a Dane," Villemann said. "It should have been them [Frederik and Storkholm].
"What happened when he was with Katja was he did his Navy Seal training ... that only happened because Katja was there, because she was supporting him.
"Also, when he had to go and perform royal duties which he didn't like, she would go over speeches with him and suggest changes and coach him. They were a real team."
In her book, Villemann describes how Mary finds it difficult to cope when Frederik goes to see his ex-girlfriends when he needs support.
Villemann said there was public sympathy for Mary and how difficult it was for her to adapt to royal life from humble beginnings in Tasmania.
But she said many feared the princess had virtually "locked herself in the royal palace and thrown away the key".
"She is trying very hard to become the perfect princess but in doing so she has lost herself," Villemann said.
"The happy-go-lucky girl from Hobart with long hair and an easy smile has gone. We have this emaciated crown princess wearing all these designer clothes. It's not natural. She is trying too hard."
-AAP