A close friend of the family has said that the late monarch accepted that she was not going to live as long as her mother.

Queen Elizabeth II’s precise cause of death will “never be known” as she’d been suffering from multiple conditions in her final year, a close friend of the Royal Family has revealed.

The official entry in the Register of Deaths said Queen Elizabeth II died of “old age” – and no other causes of death are mentioned.

Queen Elizabeth II at the Platinum Jubilee, 2022

The entry also stated the late 96-year-old died at Balmoral Castle at 3.10pm on September 8.

Now a new book, Charles III New King. New Court. The Inside Story by Robert Hardman, has revealed that the exact reason the monarch passed away will never be known, extracts published in the Mail on Sunday show.

A close friend of the family has told the paper that is because she had been suffering from multiple conditions in her final year.

Queen Elizabeth II with Prince George

They said: “She had come to realise that the medical prognosis meant she was not going to emulate her mother and reach 100, so she had been determined to make the most of that [final] year.

“She made sure she had all the family up over the summer, so that the young ones in particular would always be left with happy memories of her.”

Members of the public were informed a few hours after the passing of the Queen, with Buckingham Palace issuing a brief statement reading: “The Queen died peacefully at Balmoral this afternoon.”

It was revealed in December that Queen Elizabeth gave great thought to where she might pass away – and that she knew her time was limited.

Princess Anne said: “There was a moment when she felt that it would be more difficult if she died at Balmoral”.

This was because every monarch since the creation of Great Britain had died in England.

She added: “And I think we did try and persuade her that shouldn’t be part of the decision-making process. So I hope she felt that that was right in the end.

It was in a BBC documentary – Charles III: The Coronation Year which was screened on Boxing Day – that Princess Anne relayed some of the late Queen’s thoughts during her last days.

The Princess Royal said she felt it was “serendipity” she was at Balmoral before her mother’s death.

She also revealed that she “weirdly felt a sense of relief” when the imperial state crown was removed from her coffin which was the symbolic moment at which her role passed to her brother Charles.