Why Queen Elizabeth’s Sister Burned Princess Diana’s ‘Highly Personal’ Letters After Her Death

Princess Margaret dramatically destroyed letters that Princess Diana once wrote to her mother-in-law Queen Elizabeth II and the Queen Mother. Margaret, known as the late monarch's 'rebel sister,' burned the "highly personal" letters in a bid to protect the crown. Though the content of the private papers isn't known, a royal author gives further insight into Margaret's malicious act. 

Gareth Russell, author of the book Do Let's Have Another Drink! The Dry Wit and Fizzy Life of Queen Elizabeth the Queen Mother appeared on the To Di For Daily podcast and claimed that Margaret "burned all of Diana's letters to the Queen Mother," alongside "hundreds, maybe thousands of others," which he said is "horrifying" from a historian's perspective, per Express.

Meanwhile, another royal biographer William Shawcross echoed the same in his book, "Princess Margaret was engaged on one of her periodic 'sortings' of her mother's papers [in 1993]. On the Princess' orders, large black bags of papers were taken away for destruction rather than for ultimate consignment to the Royal Archives," and as a result, "there is no record of just what was thus lost." 

But, "Princess Margaret later told Lady Penn (who was related by marriage to Queen Elizabeth's private secretary, Sir Arthur Penn) that among the papers she destroyed were letters from Princess of Wales to Queen Elizabeth," which she said were "so private." Shawcross further wrote, "No doubt Princess Margaret felt that she was protecting her mother and other members of the family," adding that "It was understandable" but "regrettable" from a historian's viewpoint. 

Though the act in itself may sound scandalous, royal author Russell discovered that burning letters back then "used to be the equivalent of aristocrats wandering off like elephants to the graveyard. It's what they did." He further explained that aristocrats did that "because they felt that letters sent privately shouldn't ever be [public]. It was a breaking of a code almost" and in his opinion, Queen Mother must have been "fully on board" with Margaret burning the letters. 

However, when it comes to Margaret's relationship with Princess Diana, she welcomed her with open arms while also recognizing that Diana is a kindred soul who is struggling to fit into the royal family. Journalist Andrew Morton told PEOPLE, "Margaret put her arm around Diana." He also noted in his book that Margaret came to Diana's "rescue, suggesting to the Queen that [she] was having difficulties adjusting to her role and that she [Elizabeth] should cut her some slack, [and said], Just give Diana a chance."

But, Margaret felt betrayed after Diana shared unfiltered details of her troubled marital life with Prince Charles to BBC's Martin Bashir in her explosive Panorama interview. Margaret, who died in 2002 at age 71, fiercely protected the royal clan as Morton affirmed in his book that she was "always loyal" to Queen Elizabeth. And after the Panorama interview, "[Margaret] felt Diana let her sister down."