The royal family have two ways of presenting themselves to the public: the personal and the ceremonial.
At a time when their private lives are in turmoil, with the King's brother under police investigation and his second son striking out on his own in America, they can at least fall back on ritual.
Trooping the Colour, from the 41-gun salute to the coloured vapour trails of the Red Arrows' flypast, is high pomp at its pinnacle. The display of pageantry in polished breastplates reasserts both a British knack for military spectacle and the royal family's place at the heart of it.
It also anchors the family to the past. Charles III is perpetuating a ceremony first performed by Charles II, but the more important association is with Elizabeth II. His mother's constancy in the face of personal tragedy remains in living memory and is a narrative that the King must maintain.
Harry has attended no Trooping the Colour ceremonies during his father's reign (he and Meghan were last present in 2022 but did not take part) and Andrew Mountbatten-Windsor has been excluded since 2019.
So their continued absence is unsurprising, but it is nonetheless the first of the King's official birthdays since Andrew's arrest in February. Any family gathering where Andrew was once a fixture raises the issue that a man stripped of all his honours remains eighth in line to the throne.
© WireImageThe investigation into allegations of misconduct in public office relating to Andrew's friendship to the sex offender Jeffrey Epstein remains unresolved. Protesters agitating for a republic use such occasions to highlight his case. Andrew has always denied any wrongdoing.
A show of unity on the balcony of Buckingham Palace will therefore serve as a visual reminder that for the rest of the family, their core business continues. The country will be paying attention. In addition to the tens of thousands of people who attend in person, millions will be watching the broadcast. For Queen Elizabeth's last, during her Platinum Jubilee in 2023, three months before her death, viewing figures reached 7.5 million.
© Getty ImagesWhile the Prince and Princess of Wales are increasingly presenting themselves as being relatable and approachable, there is still value in maintaining a sense of mystique and grandeur that separates them from elected politicians.
This means waving from an open-topped carriage, taking salutes and watching men in bearskin hats hold drumsticks under their noses while slow marching to the tune of a Franco-German opera about star-crossed lovers. Even those parts of the occasion that seem eccentric are executed with precision.
© Getty ImagesThis year may also be the last for some time with all of the Prince and Princess of Wales's children in attendance. If Prince George enrolls at a boarding school, as he is expected to do, he would miss the ceremony as William did while studying at Eton.
