Princess Diana’s brother Charles Spencer has decided to release a book revealing the secrets of her life, coinciding with the 30th anniversary of the English princess’s death.

Titled “Swan Song: Diana, My Sister,” the book — written by Charles Spencer, better known as Earl Spencer — is scheduled to be released next month in the United Kingdom and around the world. Spencer has announced that the book will reveal the truths of Diana’s life.

Diana, the first wife of King Charles, died in August 1997 at just 36 years of age. She died when the car she was traveling in with her boyfriend Dodi Al-Fayed, being chased by photographers, sped into the Pont de l’Alma tunnel in Paris, France, and crashed.

Although Diana gained enormous popularity following the lavish 1981 wedding ceremony, problems arose in the marriage and it was dissolved in 1996. In the eulogy Spencer delivered at Diana’s funeral, he sharply criticized the British royal family.

A small note: the book, Swan Song: Diana, My Sister, is set to be published on 22 September 2026, ahead of the 30th anniversary of Diana’s death in August 2027 — so the anniversary is upcoming rather than this year, if you want to tighten that detail.