Prince Harry's dramatic departure from the Royal Family was documented in his first book Spare. Now, biographer Omid Scobie is set to release a new book after the monarchy.

It will focus on the institution and its fight for survival - including more bombshell claims about Royal Family members. The book is due to be released at the end of the month.

Ahead of its release date, an excerpt from the book Endgame has been published by US-based PEOPLE magazine. Here is a round-up of some of the most explosive claims in the book, MirrorOnline reports.

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Harry in the dark

One claim is that Prince Harry was 'kept in the dark' about the decline in the Queen's health before her death. The book alleges the Duke of Sussex was not told about his late grandmother's worsening health in the hours before she died.

The royal author adds Harry and his wife Meghan Markle had 'no idea' the Royal Family was preparing for the Queen's final hours. An extract from Mr Scobie's book reads: "The Sussexes had no idea that Buckingham Palace was already planning for the Queen's final hours and the first days of the monarchy's new era - until the duke's phone started ringing. An unknown number. He usually ignored those."

Meghan is said to have urged her husband to answer the phone and he accepted the call 'just before it stopped'. Omid said: "Harry hadn’t spoken to his father much that year, but this was not the time for any father-and-son tension.

"Charles told him he and Camilla were about to leave Dumfries House for Balmoral, where Princess Anne was already by the Queen’s side. He told Harry to make his way to Scotland immediately."

Harry 'forced to beg'

Prince Harry is said to have eventually been informed of his grandmother's ailing condition and managed to board a flight to Scotland. The late Queen's death was announced to the world just after 6.30pm - not long before the Prince's plane landed in Aberdeen.

According to the excerpt, Harry's team had to 'beg' Buckingham Palace not to announce the sad news earlier. It reads: "His team literally had to beg for them to wait for his plane to land and they reluctantly agreed to hold the statement back for a little bit, confirmed a close family source.

"But as stormy weather over Aberdeen International forced Harry’s plane to circle the airport numerous times before landing, patience at the Buckingham Palace press office wore thin — they could wait no longer and the announcement went live at 6:30pm.

"When Harry’s plane finally touched tarmac twenty minutes later, he received a text from Meghan urging him to call ASAP followed by a breaking news alert via the BBC News app with the announcement of the Queen’s death."

King Charles 'betrayal'

Another claim is that Prince Harry was left 'crushed' when he did not find out about the late Queen's death until after it had been announced to the world - and that King Charles' apparent decision to keep him in the dark is not what his grandmother would have wanted.

The excerpt says the late monarch 'would have wanted Harry to know that she had died before everyone else did'. When the Queen died on September 8 last year, it was initially reported that Charles personally called Harry to tell him the news.

But in his memoir Spare, Harry contests this and says he found out about her passing by reading about it on the BBC News website once he disembarked a flight to Aberdeen and headed to Balmoral.

It adds: "'Harry was crushed', said a friend of the duke. 'His relationship with the Queen was everything to him. She would have wanted him to know before it went out to the world. They could have waited just a little longer, it would have been nothing in the grand scheme of things, but no one respected that at all'."

Harry's real reason for quitting

The book claims Prince Harry was viewed as a 'threat to the crown' and exposed the real reason the Duke of Sussex left the Royal Family. Harry and Meghan sensationally quit the Firm and the UK in early 2020 and are now living in California.

In an excerpt from the book, Mr Scobie says Harry wanted the ability to think freely. It reads: "These are probably sad realisations that will be had far too late in the journey. In the eyes of some within the institution, Harry is a threat to the crown. His freedom to exert his own thinking outside of the confines of the institution has made him the enemy."

William's brutal response

Prince Harry's apparent rocky relationship with his brother Prince William is said to be at an all-time low. The siblings have been locked in a bitter feud for a number of years.

In Prince Harry's memoir Spare, it was claimed that William physically attacked his younger brother in a heated row at Kensington Palace. In a series of interviews earlier this year, Harry also said he wanted an apology from his family about how he was treated.

But Mr Scobie said that 'absolutely nothing has changed' between William and Harry recently. Detailing the brutal one-word response Harry received when leaving royal life, he writes: "I was talking to a source quite early on in the process, and they called Harry a 'defector' and said that was William's view.

"These were two men who once upon a time were firmly aligned in their outlook. One of them had to move on to also protect the crown."

'Brainwashing' fears

The book also claims William 'doesn't want to know' his younger brother, who he believes has been 'brainwashed by an army of therapists'. It claims: "[William] believes Harry and Meghan blindsided the family, even the Queen, with their public complaints and their 'oh so California' self-importance (an opinion he has repeatedly voiced in various ways to friends and aides during the past two years).

"Convinced Harry's been brainwashed by an 'army of therapists', William says he no longer even recognises his own brother, a source said."

Endgame is described on Amazon as 'a penetrating investigation into the current state of the British monarchy'. The book's description goes on to say: "An unpopular king, a power-hungry heir to the throne, a queen willing to go to dangerous lengths to preserve her image, and a prince forced to start a new life after being betrayed by his own family."

Endgame, which will be published on November 28, is subtitled "Inside the Royal Family and the Monarchy's Fight for Survival".

Publisher HarperCollins previously said the book will 'have the world talking' and Mr Scobie said it will reveal moments that royals should be 'ashamed of'. The headings of chapters include: 'Shaky Ground: The Queen is Dead, the Monarchy Faces Trouble', 'The Fall of Prince Andrew: Scandal, Shame and Silencing Jane Doe', 'Race and the Royals: Institutional Bigotry and Denial', 'Gloves On: Prince William, Heir to the Throne', and 'Gloves Off: Prince Harry, Man on a Mission'.