It is a rare public moment of affection between father and son and ends in a fit of the giggles.
Practising the moment he hands King Charles his ‘Stole Royal’, an embroidered band of cloth which symbolises the sacred nature of kingship, in the run-up to May’s Coronation, Prince William jokes about how fiddly the catch is and groans: ‘On the day it’s not going to go in, is it?’
‘No,’ says the King, giggling; ‘[But] you haven’t got sausage fingers like mine!’
The amusing interaction is one of the highlights of a new documentary charting Charles’s first year as monarch, to be shown on BBC One on Boxing Day.
Featuring previously unseen behind-the-scenes footage and exclusive interviews with key officials, family and senior royals, it captures the galloping pace of the last 12 months but also moments of lightness.
During rehearsals for May’s Coronation, at which he swore allegiance to his father, William is shown joking about which of his cheeks to kiss by tickling his father’s face and saying: ‘Your left cheek is better!’
Prince William is pictured with King Charles during the King’s Coronation rehearsals at Westminster Abbey in London
Charles’s fingers have attracted attention before with some saying they look like sausages
The King can also be seen warmly kissing his daughter-in-law, the Princess of Wales, and three grandchildren, Prince George, Princess Charlotte and Prince Louis, as they attend the rehearsals.
Inside the Buckingham Palace ballroom, which has been turned into a full-scale replica of Westminster Abbey complete with mannequins, Charles can also be seen urging the Archbishop of Canterbury, Justin Welby, to be rather more forceful with his crown.
The Archbishop says: ‘I say a prayer with the crown up there. And then slowly lower it, tipping forward.’
The king interjects: ‘You have to jam it on. It has to come down to here first.’
The Archbishop jokingly protests: ‘I don’t want to break your neck, Sir. It might ruin the service.’
Charles responds: ‘No, you won’t. Otherwise I promise you – it’s so huge, it’s got to be on right and I can’t do anything about it.’
Asked by Graham Usher, the Bishop of Norwich, to kneel for her anointing, the Queen says cheerily: ‘Yes, righto!’
Camilla’s great friend, Lady Landsdowne, one of her two Ladies in Attendance at the Coronation, remarks of her: ‘She knows when to be serious.
‘And she knows when to wink at a bishop, but [also] when not to, which I think is a rather endearing quality.’
King Charles at his Coronation rehearsal in Westminster Abbey
The King also remarks on the pared-down guest list as he sympathises with the Bishop of Durham, who says he is going to have to leave his wife at ‘the Novotel straight opposite Lambeth Palace’ to watch the event on television.
‘It’s so frustrating we can’t just have other halves here,’ Charles says.
The documentary, written and co-produced for Oxford Films by the Mail’s own royal expert, Robert Hardman, follows the monarchs as they watch their three crowns being reworked to fit them and their robes embroidered, with the King looking teary and emotional at times.
After the Coronation itself Lady Lansdowne reveals there was ‘quite a funny moment’ in Westminster Abbey when Camilla appeared to be backing away from the crown.
‘But I think that was just because she was worried that the Archbishop was going to tread on her dress so she was just pulling herself back,’ she says.
The Queen’s sister, Annabel Elliot, her other Lady in Attendance, adds: ‘She was obviously incredibly nervous. She doesn’t show it a lot, but I know her well enough.
‘I think he [the King] was very proud of her. And I think there was a sense of, ‘I can’t believe it. We’ve made it.’
Camilla can even be seen puffing her cheeks out in relief when they arrive back at Buckingham Palace after the formal elements of the day.
Princess Anne explains: ‘Ask any actor who comes off stage having done a performance that they really put a lot into, it’s that kind of relief.’
Charles affectionately greets his sister and kisses her hand in the same segment of footage. ‘Hello old bean,’ he says, smiling broadly.
In another amusing moment, filmed at Balmoral last summer, the King can be seen going through his red box of paperwork with his private secretary Sir Clive Alderton.
Asked to sign off on a message to the King of Sweden to mark his Golden Jubilee, Charles says: ‘Oh gracious, is this in Swedish? I hope that’s right, is it, the Swedish? You never know if somebody’s fed you something frightful to say!’
Sir Clive later tells the interviewer: ‘The King is an incredibly hard worker. I think that’s one of the things that pretty much everybody knows about him. He works till very late at night, often well beyond midnight.’
In their first year alone Charles and Camilla have undertaken 571 engagements and three state visits, met more than 2,000 people and awarded 1,000 honours.
- Charles III: The Coronation Year will be shown on Tuesday, December 26, on BBC One at 6.50pm.
James Parker is a UK-based entertainment aficionado who delves into the glitz and glamour of the entertainment industry. From Hollywood to the West End, he offers readers an insider’s perspective on the world of movies, music, and pop culture.