As two touching photographs of William, Kate and Prince George were released to officially mark the toddler's big day, the Cambridges paid their own tribute to the public support they have received in the last year.
The Duke and Duchess said: "We would like to take this opportunity on George's first birthday to thank everyone over the last year, wherever we have met them for their warm and generous good wishes."
The couple and their son have received praise both in the UK and abroad, following the birth of George on July 22 last year.
Well-wishers especially took them to heart when the Cambridges travelled with their son to New Zealand and Australia in April.
William, Kate and George were photographed at a butterflies exhibition at London's Natural History Museum.