The book will be called “Spare” and is being billed by Penguin Random House as an account told with “raw, unflinching honesty” and filled with ”insight, revelation, self-examination, and hard-won wisdom about the eternal power of love over grief.”

In a statement released Thursday, Penguin Random House summoned memories of the stunning 1997 death of Prince Harry’s mother, Diana, and the subsequent image of Harry and his brother “walking behind their mother’s coffin as the world watched in sorrow — and horror.”

“As Diana, Princess of Wales, was laid to rest, billions wondered what the princes must be thinking and feeling — and how their lives would play out from that point on,” the statement reads in part.

“For Harry, this is his story at last.”

The memoir’s title is an apparent reference to “the heir and the spare,” a phrase often used to describe royal siblings. Harry’s brother, William, is now Prince of Wales and heir to the British throne. When Harry was born, he was right behind William in the line of succession but has since been pushed down. Their father , King Charles III, assumed the throne upon Queen Elizabeth II’s death last month.

Royals watchers and the public at large have speculated endlessly since the book was first announced in July 2021.

The Duke of Sussex had already revealed a newsmaking willingness to discuss his private life when he and his American-born wife, Meghan, Duchess of Sussex, were interviewed by Oprah Winfrey for a bombshell March 2021 broadcast. The couple spoke of Meghan’s deep unhappiness with her new life in England, the alleged racism within the royal family and Harry’s fear that his wife’s life might be endangered had they remained in his native country.

Harry and Meghan stepped back from royal duties in 2020 and moved to the U.S. Harry told Winfrey that his family cut him off financially and that he helped pay for his security with money left to him by his mother. They have launched numerous initiatives, including a Netflix production deal and the nonprofit Archewell Foundation.

The 416-page book will be published in 16 languages, from Dutch to Portuguese. Harry himself — identified by Penguin Random House as “a husband, father, humanitarian, military veteran, mental wellness advocate, and environmentalist” — will narrate the audiobook. The cover features a close-up of an unsmiling, T-shirt-clad Harry’s face.

Financial terms were not disclosed, but Harry, Duke of Sussex, will donate proceeds from “Spare” to British charities. He has already given $1.5 million to Sentebale, an organization he co-founded with Prince Seeiso of Lesotho to help children and young people in Lesotho and Botswana affected by HIV/AIDS.

The book was originally tentatively scheduled for publication this year. The delay led to rumors that Harry was hesitating to say too much about his family, or was perhaps revising the narrative after his grandmother died in September. He has spoken of being estranged from his brother, although the siblings and their wives appeared in public together during the mourning period following the Queen’s death.

In 1992, Diana worked with author Andrew Morton on her explosive memoir “Diana: Her True Story,” in which she described at length her unhappy marriage to the future King Charles III.

“Penguin Random House is honored to be publishing Prince Harry’s candid and emotionally powerful story for readers everywhere,” the global CEO of Penguin Random House, Markus Dohle, said in a statement. “He shares a remarkably moving personal journey from trauma to healing, one that speaks to the power of love and will inspire and encourage millions of people around the world.”