Prince Louis "especially" had an incredible time at the celebrations to mark the Queen’s Platinum Jubilee, the Duke and Duchess of Cambridge have said.
It comes after the four-year-old entertained the nation with his antics - pulling funny faces and fidgeting during some of the pomp and pageantry.
Louis was seen letting out a howl and clapping his hands over his ears on the Buckingham Palace balcony on Thursday during the RAF flypast as his "Gan Gan" the Queen explained to him what was happening.
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The prince was also spotted being bounced on the knee of his grandfather, Charles, during the pageant on Sunday and giving his mother Catherine a kiss on the cheek and a cuddle.
He stood on his chair, waved his hands in the air, wriggled around and stuck his finger in his ear during the show.
William and Catherine thanked everyone who turned out for the long weekend of celebrations marking the Queen’s 70-year reign and stated: "We all had an incredible time, especially Louis…" followed by the wide eyed emoji.
In a personal message, alongside images from the weekend’s events, they tweeted: "What a fantastic weekend of celebrations.
"Seeing people across the nation coming together with family, friends and loved ones has been extremely special.
"Thank you to everyone who turned out to show their gratitude to The Queen and her inspiring 70 years of leadership."
The thread continued: "From the crowds on the Mall to communities hosting street parties up and down the country, we hope you had a weekend to remember.
"We all had an incredible time, especially Louis…"
The Queen was absent for much of the extended Bank Holiday weekend events, after finding the first day enjoyable but tiring.
In a message of thanks, the 96-year-old acknowledged this but said her "heart" had been with well-wishers.
The Duchess of Cornwall, patron of the Big Lunch, estimated that up to 18 million people could have taken part in Jubilee street parties.
The Queen expressed her hope this "renewed sense of togetherness" would be felt for years to come.
After the outpouring of public affection during her balcony appearance, the Queen said she was "humbled and deeply touched" so many people had taken part in the celebrations.