"I can't bear this bloody thing!" King Charles' at signing ceremony at Northern Ireland's Hillsborough Castle over frustration of an inadequate pen. Video / AP
"Can you please be quiet? There's a call."
Those were the words told to an American journalist who was at King Charles' Scotland home to interview Camilla just hours before Queen Elizabeth II died on September 8.
NBC's Today host Jenna Bush Hager, the daughter of former US president George Bush, has given rare insight into what was happening behind closed doors when Charles, 73, got the call his mother's health was deteriorating.
Bush Hager, 40, said on the US programme she and her husband Henry Hager had an intimate dinner with the then Prince of Wales at Dumfries House on the evening of September 7. The Duchess of Cornwall was unable to join as her British Airways flight had been delayed.
In what possibly hints at how rapidly the Queen's health took a turn for the worse, the TV anchor said Charles did not appear to show any signs that the Queen's health was a concern, adding they "had a wonderful evening filled with conversation that felt joyful."
"He (Charles) said: 'My darling wife is so sad (she can't make dinner) … She can't wait to sit down with you tomorrow," Ms Bush Hager said on NBC. "So I think this (the Queen's death) was sort of a surprise."
The following morning, Bush Hager returned to Dumfries House with her crew to set up for their interview with Camilla around 1.30pm.
Bush Hager said she sensed something was awry around 12.30pm, when she heard "running up and down the halls."
King Charles didn't seem to know the Queen's health was declining just hours before her death. Photo / AP
"It was her (Camilla's) team and his (Charles') team … They came in and said, 'Can you please be quiet there's a call'.
"We were right (near) then Prince Charles', now King Charles III's, office. They said, 'He's on a call, can you please be quiet?' And then all of a sudden we heard a helicopter.
"They said, 'The Queen is ill and they have gone and rushed off to be with her.'" Just a few hours later, Buckingham Palace announced Her Majesty had passed away "peacefully" aged 96.
Charles immediately ascended to the throne and his wife Camilla became the Queen Consort, while Prince William was given the title Prince of Wales.
Despite his grief, Charles has had a whirlwind of engagements since his mother died.
He spent most of Tuesday in Northern Ireland, after flying in from Edinburgh on Tuesday morning.
The King and the Queen Consort arrived in Belfast late on Tuesday morning (UK time) and were greeted by the Lord Lieutenant of Belfast, Dame Fionnuala Mary Jay-O'Boyle, and Northern Ireland Secretary Chris Heaton-Harris.
The royal couple then travelled to Hillsborough Castle in County Down, the Royal Family's only residence in Northern Ireland.
King Charles III and the Queen Consort leave Clarence House, for Westminster Hall. Photo / AP
Charles was seen grinning as he greeted children who had gathered outside to meet him, as well as well-wishers offering flowers.
At the castle, the new King met the nation's political leaders, including senior members of Sinn Fein — the republican party which was closely associated with the IRA during the Troubles and who refuse to swear allegiance to the Crown.
At Hillsborough, Charles pledged to follow the "shining example" his mother had set during her "long life of public service".
The King then travelled to St Anne's Cathedral in Belfast for a Service of Reflection for the Queen.
On Monday night, Charles and his three siblings — Prince Andrew, Princess Anne and Prince Edward — held a vigil over the Queen's coffin at St Giles' Cathedral in Edinburgh.
Then, on Tuesday night, he hosted a private gathering at Buckingham Palace with close family, including Prince William, Prince Harry, Kate Middleton and Meghan Markle, to receive the Queen's coffin.
Her Majesty's coffin touched down at RAF Northolt shortly after 7pm (UK time) and was driven to the Palace, where she will spend one final night before lying in state at Westminster Hall.
