Nearly three decades after Princess Diana's death, her younger brother is finally telling her story himself - and Charles Spencer says he wants to correct the "untruths" that have become accepted about the world's most famous princess.
The 9th Earl Spencer has announced Swan Song: Diana, My Sister, a deeply personal new book scheduled for publication on September 22, 2026, as the 30th anniversary of Diana's August 31, 1997 death approaches next year. It will be the first time Spencer has written at length specifically about his sister and their life together.
And this apparently isn't going to be another detached royal biography.
According to publisher Penguin Michael Joseph, Spencer will tell the story from the perspective almost nobody else can offer: Diana's only brother. The book will move from their childhood together through Diana's extraordinary transformation into a global celebrity and ultimately to the tragic week surrounding her death in Paris.
Spencer says the timing isn't accidental. With another major Diana anniversary approaching, he has been inundated with requests to talk about his sister. But rather than continue allowing other people to define her story, he decided it was time to put his own memories on the record.
And he appears particularly interested in challenging the mythology that has accumulated around Diana.
Spencer says there are "untruths that have become accepted" in the decades since her death, and he wants Swan Song to present what he regards as the truth about the woman he actually knew.
That promise alone is likely to make the book irresistible to royal watchers.
Diana has been the subject of countless biographies, documentaries, television dramas and competing accounts from royal insiders. But Spencer isn't another commentator looking from the outside. He grew up alongside her, witnessed their parents' difficult divorce and watched his sister go from Lady Diana Spencer to the Princess of Wales - and eventually one of the most photographed women on earth.
He remembers a very different Diana behind the headlines, describing his sister as a "one-off, dynamic character" who was "full of love," while also emphasizing the charisma, humor, complexity and vulnerability that accompanied her enormous public appeal.
There is another reason Spencer's decision carries considerable weight: he was the man who delivered one of the most unforgettable speeches in modern royal history.
At Diana's funeral in Westminster Abbey in September 1997, Spencer delivered an extraordinary eulogy in which he fiercely defended his sister and criticized the relentless media attention surrounding her. His words were widely interpreted as containing pointed criticism of the royal establishment as well.
Now, almost 30 years later, Spencer says the new book continues that mission of speaking truthfully about Diana.
The timing could hardly be more explosive for the royal family.
Diana's sons, Prince William and Prince Harry, have spent recent years following increasingly separate paths, while memories of their mother remain central to both men's public identities. Spencer is their maternal uncle, meaning any new revelations about Diana's marriage, private struggles, final years or relationship with the monarchy will inevitably be examined for what they might mean for her sons as well.
But the publisher is positioning Swan Song as more than a royal tell-all. Daniel Bunyard of Penguin Michael Joseph describes the book as both revealing and emotionally significant, while Spencer says he wants it to serve as a celebration of Diana for people who remember her and an introduction for younger readers who were born after her death.
The publisher clearly expects interest well beyond Britain. World all-language rights have been acquired, with publication planned internationally and translations into 12 languages. Penguin Press will publish the book in the United States.
Spencer is already an established bestselling historian and memoirist. His previous books include The White Ship, To Catch a King and the intensely personal 2024 memoir A Very Private School. But Swan Song places him in entirely different territory.
This time, he isn't primarily excavating Britain's distant history.
He's writing about his sister.
And perhaps the most tantalizing part of the announcement is what Spencer hasn't revealed yet. We know the book will cover their childhood, Diana's extraordinary public life and the traumatic period surrounding her death. We know he intends to challenge stories he believes are false.
What we don't yet know is which "untruths" Charles Spencer intends to confront.
That question alone may ensure Swan Song: Diana, My Sister becomes one of the most closely scrutinized royal books in years.
Nearly three decades after Diana's death, thousands of books and headlines have attempted to explain who she really was.
On September 22, her brother gets his turn.
