The Prince of Wales left a lasting impression on hundreds of fans who turned up at Windsor Castle to pay their respects to the Queen on Saturday. The royal couples, known as the Fab Four, arrived as a surprise to thank mourners who had gathered outside, and shared handshakes, hugs, smiles and tears.
But it wasn't just members of the public who had special exchanges with Prince William and Harry - many gorgeous dogs felt the love too. A touching exchange was captured on camera as William commented on how important dogs are during dark times.
For the latest updates as the world mourns the Queen and King Charles III's reign begins, follow our live blog.
In the video, Kate Middleton is seen individually speaking to members of the public and shaking their hands.
"Thank you so much for coming down, I appreciate it," the Duchess says, smiling.
As William moves towards his wife, he thanks somebody in the crowd and waves as if he is about to move on.
Then a smile lights up on his face and he points towards a dog, saying to Kate: "Did you see that doggie as well?"
Kate stops to stroke the pet and the pair look at each other lovingly, as William asks the dog's name.
"Hello, Fergus," he says, followed by: "Doggies at this time are very important."
The heartwarming comment made Kate and fellow spectators smile, and touched the hearts of people online.
Lyndsey Phillips, who filmed the clip, said: "Feel so lucky that we were able to be at Windsor Castle when Prince William, Kate, Prince Harry and Meghan were doing their surprise visit to take in all the wonderful flowers and tributes."
Lyndsey shared the footage on Instagram and royal fans were besotted with the sweet moment.
One commented: "Their joy over that dog is so sweet!" while another said: "The way they take a moment for the little dog."
"The Duke and Duchess of Sussex are so kind, the hugs and the smiles on peoples faces seeing them... And even the dogs got lucky," a third wrote.
Just like his late grandmother, William is a fond dog lover - he currently owns a black cocker spaniel puppy named Orla, who was a generous gift from the Duchess of Cambridge 's brother.
The Queen proudly cared for more than 30 corgis across her lifetime and was often photographed with her pets.
Her devotion to dogs made a huge impact on animal charities, fellow owners and dog lovers during her 70-year reign.
Kay Hogg, secretary of the Welsh Corgi League Scottish sector, said the corgi community was saddened at the news of her death.
She said: "We are very, very sad. Everywhere the Queen went there were always corgis. She grew up with corgis and everybody associated corgis with the Queen.
"We feel as though, although there is a corgi league and a society, we've actually lost part of our world. She did so much for the breed, always had corgis by her side all her life."
You can leave your tributes to Queen Elizabeth II here .