The royals were out in force as they came together to mark the first Trooping the Colour of King Charles' reign.
Even his grandchildren Prince George, Princess Charlotte and Prince Louis took part by riding in a carriage to watch the impressive military ceremony at Horse Guards Parade.
With their parents the Prince and Princess of Wales required to be on the parade ground, it seems it fell to the Duchess of Edinburgh to keep an eye over the kids as they watched the service from a nearby balcony.
TV cameras picked up the moment eight-year-old Charlotte chatted to her great-aunt Sophie as they looked out over the parade ground together.
And some royal fans were convinced that Sophie could be seen giving Charlotte some stern words, telling her to "sit down".
However, a professional lip reader has dismissed this and believes the pair may have in fact been talking about how much of the parade was left.
He told the Daily Star that Charlotte appears to ask Sophie: "Sophie, how long will it be?"
To which the duchess replies: "I think it's now."
The moment came before Charles marked his first Trooping the Colour as sovereign with a Buckingham Palace balcony appearance where a boisterous Louis stole the limelight yet again.
Charles and Queen Camilla acknowledged with a wave the thousands of well-wishers in The Mall who sang the National Anthem and gave three cheers after the King’s official birthday was celebrated with a display of pomp and military pageantry.
Also on the balcony were the Princess Royal, and her husband Vice Admiral Sir Tim Laurence, the Duke and Duchess of Edinburgh, the Duke and Duchess of Gloucester and the Duke of Kent.
But all eyes were on the King’s five-year-old grandson, Louis, who rose to the occasion by saluting during the traditional Trooping flypast, which was extended because the coronation aerial display had been cut back in May due to bad weather.
The young royal, whose antics during some of the late Queen’s Platinum Jubilee celebrations last year endeared him to many, also seemed to pretend to ride a motorcycle or bike with his arms outstretched and covered his ears as planes roared overhead.
The day saw many milestones, from the King becoming the first monarch in more than 30 years to ride a horse throughout Trooping the Colour and it was a similar period since five of the nation’s most prestigious regiments had gathered to celebrate the sovereign’s official birthday.
