The Cambridge children Prince George, Princess Charlotte and Prince Louis were overjoyed to meet their idol Sir David Attenborough last week. Prince William, Kate Middleton and their three children welcomed the legendary naturalist to Kensington Palace, meeting him outside in the garden after school on Thursday.

The Duke and Duchess of Cambridge took to their Instagram and shared photographs from the meeting. Prince George, seven, Princess Charlotte, five, looked almost starstruck by their encounter with Sir David Attenborough. And, Prince William and Kate Middleton appeared to be amused with their kids reaction.

The TV star on his part did not disappoint his young hosts. The 94-year-old presented George with the fossilised tooth of a giant shark that he excavated during a family holiday in Malta in the late 1960s. In another photograph, George is seen excitedly examining the tooth, as his little brother Louis, sitting near their father, looks on.

"It was very sweet, all three children were playing with it," a source told Hello! magazine. Attenborough was at the Palace to watch his new film, "David Attenborough: A Life on our Planet," with the duke. The two men sat together in the garden at Kensington Palace, both under blankets to protect them from the chilly autumn weather.

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Aides arranged out two director's chairs with their names on, but William and Attenborough decided to sit in the wrong ones. The veteran broadcaster, in what he has called his "witness statement", shares some of the defining moments of his career and the devastating changes he has seen.

In "Prince William: A Planet for Us All," William said that "fatherhood has given me a new sense of purpose" and "to hand over to the next generation, the wildlife, in a much better condition."

Kate Middleton
Duchess of Cambridge (L), talks to David Attenborough and museum director Sir Michael Dixon (R) as she attends the reopening of Hintze Hall at the Natural History Museum in London on July 13, 2017. Getty

"A Life on Our Planet" is available in theatres from Monday, Sept. 28 and on Netflix from Oct. 4.