A wobbly crown, playful Prince and a King’s joke about ‘sausage fingers’ – behind the scenes at the coronation

It was one of the most watched TV events of the year, but it’s the moments we didn’t see that are the most fascinating. Harry Mount pulls up his chair for a preview of the Boxing Day documentary that captured it all on camera

King Charles III and Queen Camilla in coronation gowns and crowns at Buckingham Palace on the big day (BBC/Oxford Film and Television)

Trigger warning for the Duke and Duchess of Sussex. Do not snuggle up on Boxing Day for the BBC’s Christmas schedule offering – Charles III: The Coronation Year. There isn’t a single mention of the Montecito couple in the 90-minute programme – although you do briefly glimpse them, at the edge of the screen, in the moving footage of Elizabeth II’s funeral. Nor is Princess Diana mentioned once.

The omission is fair enough. This charming behind-the-scenes film is about two things: the build-up to this year’s coronation after the Queen’s death; and the day-to-day work of Charles III and Queen Camilla. The Sussexes now feature in neither aspect of royal life – and after a year of dignified royal silence in the face of the publication of both Spare and Endgame, this programme speaks for itself.

A senior source tells me the King has wisely decided to emulate his late mother and not give any direct interviews. Instead, the film’s writer, Robert Hardman, the author of the first biography of the King, Charles III, out in January, has got some marvellous never-seen-before footage of the King and Queen going about their royal duties – and taking the odd break from them.