One of these charities is the Whitley Fund for Nature, which the Princess Royal is a patron of. The charity offers “long-term” support to conservationists who lead solutions to the global biodiversity and climate crises.

This includes awarding some of these conservationists to help them scale up their ideas.

Ahead of Sir David’s birthday next week, Anne paid tribute to Sir David in a recent film, and his efforts at helping with conservation and the environment.

She said: “He has made such an impact and I’m sure his experience made such a huge difference to so many people being able to say, it’s worth trying.

"I hope that many of our winners took inspiration from that because, my goodness, they made such a difference."

The Princess Royal has been a dedicated patron for the Whitley Fund for Nature since 1999, with Sir David having been a trustee and ambassador for the charity.

He has supported the charity since 1998.

Sir David has worked and met with a number of royals throughout his life, including Prince William, King Charles and Queen Elizabeth II.

The Prince of Wales wrote on social media: "As he turns 99 today, in his new film, Sir David has once again reminded us of the need to protect natural habitats - this time those beneath the ocean.

"He has dedicated his life to ensuring we understand the realities of what mankind is doing to the planet. However hard-hitting his message is, Sir David always leaves us with a sense of hope and optimism that all is not lost and this film is no different.We must act together, with urgency, to restore our oceans.Happy Birthday, David. W."