The “sanctuary” that the Princess has found in the natural world since her cancer diagnosis and her recognition of the bond between nature and humanity is an understanding she shares with her father-in-law, King Charles.

The King was also diagnosed with cancer last year and spent a short time in hospital on Thursday after experiencing side effects from his treatment.

The monarch advocates a holistic approach to the challenges facing the planet and has been a lifelong champion of the environment, even before it became a mainstream preoccupation.

On Commonwealth Day, earlier this month, he said that restoring the “disrupted harmony of our entire planet” was the most “important” task facing humanity.

The Princess’s words accompanying her video echo the King’s philosophy of harmony, which sees everything in nature as interconnected, including ourselves.

The Queen has also emphasised that the monarch is a “countryman to his very core”. Writing in Country Life magazine in 2022, she said: “It’s the place where he is most happy and relaxed, an integral part of his heart and soul.

“Whether he’s hedge-laying in the pouring rain, striding, like a mountain goat, up impossibly steep Highland hills, planting trees in the arboretum or pruning at Highgrove, this is where he finds true peace,” she added.

The Princess came under scrutiny following her Mother’s Day message last year, which included a photo of her and her children that was said to have been taken by William in Windsor earlier in the week.

Questions were raised that the image – the first of the Princess to have been released after she underwent abdominal surgery a few weeks earlier – may have been manipulated before it was posted on social media.

It was withdrawn by international picture agencies later the same day.

The Princess publicly took the blame for the manipulated photograph and issued a personal apology for the “confusion”.

She said: “Like many amateur photographers, I do occasionally experiment with editing. I wanted to express my apologies for any confusion the family photograph we shared yesterday caused.

“I hope everyone celebrating had a very happy Mother’s Day. C.”