Princess Anne was grieving the death of her mother but still proved to be invaluable in the hours after the Queen's passing. Ever practical, Anne took charge at Balmoral and took it upon herself to ensure members of the family got the chance to say goodbye for the very last time.
That included Prince Harry, who arrived at the Scottish estate some hours after Her Majesty had died, with Anne proving to be a pillar of support.
Writing in his new book, 'Charles III: New King, New Court: The Inside Story', author Robert Hardman lifted the lid on the hours after the Queen's death, and the important role that Anne played.
"One of the King's first decisions was to ask Princess Anne to take charge of the house party now rapidly expanding at Balmoral Castle" Mr Hardman wrote in the book, serialised by Mail Online. "The Princess Royal would prove indispensable over the next few days. She was there when Prince Harry eventually arrived.
"She greeted him with a hug and escorted him up to the Queen's bedroom, where he was left to pay his respects to his late grandmother. Harry then joined the family dinner downstairs. Neither his father nor his brother was there, however. The King and Queen Camilla had, by now, returned to Birkhall, their home on the Balmoral estate."
It comes after a new memo, recorded by the late Queen's private secretary, Sir Edward Young, confirmed that she died peacefully in her sleep.
It appears in the book, and reads: "Very peaceful. In her sleep. Slipped away. Old age. She wouldn't have been aware of anything. No pain."
The biography also alleges that when the footman opened a red box of paperwork on the Queen's deathbed, two letters were found - one addressed to King Charles and the other to Sir Edward, with the contents never likely to make it into the public domain. Mr Hardman wrote: "Even on her deathbed, there had been work to do. And she had done it."
Other extracts from the book revealed that King Charles and Queen Camilla spent an hour with the Queen before she passed away on 8 September 2022, and that the news of Her Majesty's death was shared with Charles as he returned to Balmoral after picking mushrooms.
Fears about the Queen's health led to Charles going over his notes on London Bridge, the codeword for the operation about the Queen's death, on a helicopter ride over to Balmoral, and he personally told Prince William and Prince Harry to head to Balmoral, although it was believed at the time that the monarch would have days rather than hours left.
The biography also revealed that Princess Anne and the Queen's closest friend, Angela Kelly, would alternate at her bedside, while the Rev. Kenneth MacKenzie read to the Queen from the Bible.