Prince Charles has revealed he was nearly reduced to tears when Prince William praised his hard work on the Duchy of Cornwall.
The Prince of Wales said he was "deeply touched and moved" when he heard his eldest son say he had been thinking about how to maintain the picturesque estate when he was no longer around.
He spoke out during a two-part ITV documentary giving a behind-the-scenes glimpse into the Duchy, which covers more than 130,000 acres across 23 counties, to mark his 50th working year as the Duke of Cornwall.
Prince Charles said: "It practically reduced me to tears because I suddenly thought just hearing that from him has made the last 50 years worthwhile."
He added: "Confronting your own mortality is a very good thing if I may say so - it’s quite good for the soul."
Earlier in the programme, Prince William told one of the Duchy's tenants, farmer Mervyn Keeling, that his father had always impressed on him the importance of passing the Duchy down through generations.
"I’ve started to think about how I will inherit the Duchy one day and what I do with it," said the Duke of Cambridge.
Asked by Mr Keeling if having children himself gave him even more of an incentive to preserve his father's legacy, he said: "Yeah absolutely".
In the last two decades, Prince Charles, who has been vocal about the need for action on climate change, has increased Duchy woodland by more than half.
"I just pray that climate change and all the horrors we are facing now if we don't do something about it won't completely destroy all this effort," he said.
"To me it's absolutely crucial that we don't battle with nature and actually work with it, with her."
Prince Charles: Inside the Duchy of Cornwall starts at 9pm on October 24 on ITV.