Princess Margaret’s Lady-in-Waiting Anne Glenconner Opens Up: ‘We Would Roar with Laughter’

For more than three decades, Lady Anne Glenconner was not just a close confidante to Princess Margaret, she was also a witness to history. But looking back, what she treasures most are the personal, intimate moments they shared.

“Often when we did official things, funny things happened,” Glenconner tells PEOPLE of her memories of Queen Elizabeth‘s younger sister, whose acerbic wit and bon vivant lifestyle became her hallmarks. “That was the point of having a friend as a lady-in-waiting – once we were alone we could laugh. I never laughed so much. We would roar with laughter.”

Glenconner, 87, is opening up like never before in a candid new memoir, Lady in Waiting: My Extraordinary Life in the Shadow of the Crown. Already a sensation in the U.K., it will be released in the U.S. on March 24 – and this week’s issue of PEOPLE features an exclusive excerpt.

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Hal Shinnie Lady Anne Glenconner

The book charts Glenconner’s extraordinary life, from her aristocratic childhood growing up in a stately home through being one of the Queen’s attendants at her 1953 Coronation to her rocky marriage to an unfaithful Colin Tennant (who later became Lord Glenconner). The journey also features sparkling tales of exotic escapes to the Caribbean island of Mustique, where Margaret built a home, and an eyewitness account of Margaret’s tempestuous marriage to photographer Antony Armstrong-Jones.

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Lady Anne Glenconner and Princess Margaret

Although Margaret, who died following a stroke in 2002, luxuriated in a glamorous lifestyle, Glenconner says it is the simpler times with the princess that she recalls above all others.

“We used to go for walks and to the beach, or we would garden. She used to lay my fires because I wasn’t a Girl Guide! My most precious moments were when we just together, enjoying our life,” she says. “Without our husbands.”

For much more on the Lady Anne Glenconner and her extraordinary life, pick up an issue of PEOPLE on newsstands Friday.