There could only be one true star of the show at her Platinum Jubilee. But ever gracious, the Queen was happy to indulge a little scene-stealer by her side at Trooping the Colour, as four-year-old Prince Louis stepped into the limelight as her most entertaining balcony companion of all.
The youngest child of the Duke and Duchess of Cambridge secured himself a prime position on the Buckingham Palace balcony next to the Queen, known to him and his siblings as "Gan Gan".
There, as the Armed Forces put on a spectacular flypast to mark the Queen's Platinum Jubilee, he cemented his role as the lively younger brother charming family and nation alike.
Jumping up and down with excitement and covering his ears to protect against the noise, he was so pleased with his own waving that, according to a lip reader, he told the royals: "Look at me waving!"
Engrossed in conversation about helicopters and planes with a patient Queen, at one point he appeared to ask delightedly whether there was yet more to come.
All three Cambridge children exclaimed "wow" over the loud noise of the jets, as the Duke and Duchess of Cambridge pointed to the skies.
As the Duchess explained that a formation had spelled out the number "70" in the sky, Prince Louis began to count on his fingers while the smiling Queen said: "That's very clever, that must have taken a lot of practice."
At one point, oblivious to their long history of watching flypasts, the four-year-old Prince turned around to check that the Queen and Prince of Wales could also see the planes that had so amazed him.
The arrangements for Trooping the Colour, the spectacular opening event of the jubilee weekend, placed the Cambridge children at the centre of the Royal family, making their debut in a carriage for the occasion and allowed on the palace balcony under the Queen's specific instructions.
To the delight of royal-watchers, they were also photographed in high spirits, playing games with their young royal cousins while tucked nearly out of sight at Horse Guards Parade.
Their moment in the spotlight began at Buckingham Palace, where they climbed into an open carriage with their mother the Duchess of Cambridge and step-grandmother the Duchess of Cornwall.
Waving goodbye to their father Prince William, who was on horseback, they set off waving cheerfully at thousands of wellwishers lining the streets to see them.
"Wow," said Prince George, echoed by a giggling Princess Charlotte as they saw how many people had flocked to The Mall to celebrate the Queen.
"This is wonderful," the Duchess told them encouragingly. "Look at all these people!"
"This is great," George agreed, according to lip reader Kate Evans.
It was the first time any of the children had been in a carriage for Trooping, thought too young in previous years and then losing out thanks to modified lockdown ceremonies.
On Thursday, they more than made up for lost time.
Prince Louis was the most exuberant of the three, pointing and waving theatrically out of both sides of the carriage from his seat between his two older siblings.
At one point, big sister Charlotte lay her hand gently on Louis' waving arm, appearing to think he had been getting a little carried away in his crowd-pleasing duties.
All three children acknowledged the cheering crowds and peered around them, squinting in the bright sunshine.
Prince George, eight, wore a smart suit and tie, with seven-year-old Charlotte in a blue dress with plaits and a ribbon in her hair, and little Louis, four, in a white and light blue naval-themed outfit.
As they entered Horse Guards Parade, the Cambridge children all dipped their heads to salute the Colour, having been well-versed in the meaning and traditions of the Trooping ceremony.
"You can look up now," their mother told them approvingly, after they had shown their respect.
At Horse Guards, the Duchesses and children climbed the stairs to the Major General's Office to watch the military ceremony from above.
There, the children were reunited with their cousins Isla and Savannah Phillips, and Mia and Lena Tindall.
Younger children Lucas Tindall, August Brooksbank and Sienna Mapelli Mozzi were not seen at the windows, and Archie and Lilibet Mountbatten-Windsor were not thought to be there.
Prince Louis saluted the troops below him while Princess Charlotte was seen engrossed in a hand-clapping game with eight-year-old Mia.
The high-jinks of cousins the Cambridges, Phillips and Tindalls have become part of the annual Trooping the Colour event, entertaining viewers around the world with their friendship.
This year, after careful consideration from the Queen, George, Charlotte and Louis were the only small children allowed on the Buckingham Palace balcony, along with the Wessexes' teenagers Lady Louise Windsor and Viscount Severn.
After the military parade had ended, the Cambridges returned to Buckingham Palace by carriage and walked onto the balcony with the working Royal family for the grand finale.
By chance or design, the Queen ended up flanked by the Prince of Wales on one side, and Prince Louis on the other, looking momentarily a little perplexed as her young companion tried to squeeze past her.
As the Duchess of Cambridge tried valiantly to keep her youngest son focused on the skies, he clamped his hands over his ears to block out the noise and put his elbow on the balcony with his chin in his hands.
But as the excitement of the flypast built, he jumped up and down on the spot, exclaiming to the Queen, Prince Charles, his mother, and anyone else who would listen about the helicopters and planes he could see.
The Queen appeared charmed, pointing out the aircraft she thought her great-grandchildren might be interested in.
"Dad, look at those planes, they are so big," said Prince George, according to the lip reader.
"Amazing," said Princess Charlotte.
At the all-important moment of the National Anthem, Prince George and Princess Charlotte stood in perfect politeness, arms by their sides, with Prince Louis joining them faultlessly to begin with before looking around in astonishment.
As they left the balcony to retire inside the palace for lunch, the children all gave a final small wave to crowds who cheered from outside the gates.
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