Prince William has the sweetest picture of Prince George and Prince Philip in his office

The royal previously released that picture following his grandfather's death

prince william and george

The Duke of Cambridge took to Instagram on Friday morning to promote a new book about the Earthshot prize, Earthshot: How to Save our Planet, and in doing so, he showcased the most adorable family portrait.

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In the 15-second video released on social media, Prince William could be seen typing on a typewriter, but fans couldn't help admire an adorable family picture that was shown just behind him.

WATCH: Prince William has the sweetest picture of Prince George in his office

The picture in question is one that the father-of-three released following the death of his grandfather the Duke of Edinburgh, and shows Prince Philip and a two-year-old George sat together in a horse carriage.

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The candid snapshot was taken by the Duchess of Cambridge outside her and William's former home in Norfolk.

The release of the video comes on the same day that the royal opened up The Earthshot Prize, revealing that an incredible trip sparked the idea for it.

Prince Philip and Prince George together in Norfolk

Jason Knauf, CEO of The Royal Foundation, said: "The challenge The Duke set himself was 'What is the maximum positive personal contribution I can make in the next ten years in the fight against climate change? What am I going to do in the next decade that means I can look my children in the eye and say that I did my bit?' Every aspect of the Prize bears the stamp of his contribution."

In an introduction to Earthshot: How to Save Our Planet, Prince William speaks about the early conversations that led to the creation of The Earthshot Prize and why President John F. Kennedy's Moonshot programme, which united millions of people around the goal of reaching the moon, was behind his inspiration.

The future King says the crucial moment was when he made an early-morning trip to try to catch a glimpse of black rhino in Namibia.

William writes in the book's introduction: "The rich wildlife that I saw thriving on that visit struck a real chord. The community conservancy model is a prime example of how a simple, positive solution can have wide-reaching benefits for both humans and nature.

"Most importantly of all, it is a success story that can be replicated and scaled. I wanted to find a way to bottle that innovation and community spirit and mass-produce it globally."