Ms Brown – who authored The Diana Chronicles – will publish The Palace Papers: Inside the House of Windsor – The Truth and the Turmoil.
Ms Brown said: “This is, above all, the survival story of a family in which the pre-eminence of duty is in constant tension with the very human desires of love, ambition and the longing for escape. Writing it has been a fascinating journey.”
Ben Brusey, the publishing director at Century, added: “The Palace Papers is a tour de force in every sense – the most insightful, enjoyable and substantial account of the Royal family I have read.
“Only Tina Brown could have written it, with her impeccable sources and deep knowledge of the institution.
“Tina masterfully takes readers inside the palace walls, and to a place of understanding that Netflix’s The Crown could only dream of.
“Publishing in extraordinary times for the Royal Family, I know The Palace Papers will add richly to the public debate.”
As well as looking at the abuse allegations surrounding Prince Andrew and his friendship with convicted sex offender Jeffrey Epstein.
The Palace Papers: Inside the House of Windsor – The Truth and the Turmoil will hit shelves ahead of Harry’s own intimate memoir.
In July, the Duke of Sussex announced a deal with Penguin Random House publishers and said he would be revealing his “highs and lows” in the memoir.
Proceeds will be donated to charity but specific details about the amount have yet to be revealed.
The memoir, which will also be published in an audiobook version, is to offer an “honest and captivating personal portrait”.
A statement about the book was shared on Archewell.com and said the memoir will represent the “definitive account of the experiences, adventures, losses and life lessons that have helped shape” Harry.
Speaking about the book, Harry said: “I’m writing this not as the prince I was born but as the man I have become.
“I’ve worn many hats over the years, both literally and figuratively, and my hope is that in telling my story — the highs and lows, the mistakes, the lessons learned — I can help show that no matter where we come from, we have more in common than we think.
“I’m deeply grateful for the opportunity to share what I’ve learned over the course of my life so far and excited for people to read a firsthand account of my life that’s accurate and wholly truthful.”
Royal commentator Ingrid Seward warned Prince William is likely to come out worst in Harry’s new memoir.
Ms Seward claimed: “William is probably the one that will come out of this worst of all because there is a row between William and Harry and basically if Harry says things that are inappropriate about the monarchy, that is William’s future.
“It’s not Harry’s future, he is out of it now, but it is William’s future.”
She added: “Of course, everyone forgets poor old Prince Charles, who has remained very very quiet about all of this.
“It is his son and how hurtful can it be for him to hear Harry say that his father hasn’t been a great father – which is more or less some of the things he has already said.”
Source: EXPRESS CO UK