Leaked letters exchanged between Prince Philip and Princess Diana in 1992 portray the late duke as sympathetic and fatherly toward his daughter-in-law, broadcaster and author Gyles Brandreth said, arguing the public perception of Philip as unsympathetic was unfair.
Brandreth, who knew Philip for more than four decades, said the duke used the correspondence to counsel Diana during a turbulent period in her marriage to Prince Charles and habitually signed the notes "With fondest love, Pa." The letters resurfaced in public debate after extracts were leaked in the early 2000s and featured in evidence at Diana's inquest in 2008.
In his 2021 book Philip: The Final Portrait and in interviews, Brandreth said the letters were "sympathetic, but unsentimental, direct, but to a purpose," and that Philip confronted Diana with "home truths" intended to make her think about her marriage. Brandreth told the duke at one point that the public saw him as a "grouchy old man, unsympathetic to his daughter-in-law," a view Brandreth said did not match the tone of the private correspondence. Philip reportedly replied, "I've just got to live with it. It happens to a lot of people."
The correspondence became a focus of official proceedings when complementary therapist Simone Simmons told the 2008 inquest that two of Philip's letters had been "cruel" and had upset Diana. Palace officials said in 2002 that the original letters Philip sent were lost; the statement added that Philip retained copies of the letters he had written and still held Diana's original replies. Some letters were later published after they were leaked, with former royal butler Paul Burrell named at the time as a source and reports saying the duke had attempted to block publication.
Friends and acquaintances of the princess described the letters as meaningful to Diana at a time when she felt vulnerable. Brandreth said Diana would often open a letter, burst into tears and share it with close confidantes, including Rosa Monckton and Lucia Flecha da Lima. Those friends, Brandreth recounted, considered the letters "good" and said Philip had been trying to help.
All of Philip's letters to Diana were signed "With fondest love, Pa," and he and Queen Elizabeth II sometimes referred to themselves as "Pa and Ma." Brandreth said that, as an "outsider" who had also married into a royal family, Philip understood some of the pressures Diana faced and sought to offer guidance drawn from his own experience.
The direct exchange of letters effectively ended after Charles and Diana separated in December 1992, although Diana continued to meet senior royals, including the duke and the queen, at formal events. The publication and discussion of the letters contributed to a longer debate about the royal family's response to Diana's struggles and her death in 1997, when public anger over perceived institutional failures intensified scrutiny of individual family members.
After Diana's death, Philip was frequently described by those close to the family as a counselling presence for her sons, William and Harry. When Philip died in 2021, the Prince of Wales, now King Charles III's son, paid tribute saying Philip's "enduring presence" had guided him "both through good times and the hardest days" and that Philip would be remembered as a figure his own children would cherish.
The letters remain a contested part of the royal archive: supporters of Diana and critics of the monarchy have cited them as evidence of private attempts at intervention, while others, including Brandreth, have argued they reveal a more compassionate figure than some public portrayals allowed. The episode underscores continuing public and historical interest in the private communications and relationships that shaped the modern monarchy.