Prince Charles hinted it was time for new blood in an interview for a two-part documentary series commissioned by ITV to mark the anniversary.
The first episode, broadcast at 9pm on October 24, offers a behind-the-scenes glimpse into the Duchy of Cornwall, which covers more than 130,000 acres in 23 counties.
The estate was established by Edward III to provide a private income for his son and heir to the throne, Edward, later known as the Black Prince, and its purpose remains the same today.
During the hour-long episode, Charles is seen living up to his reputation as a hands-on duke – pruning, hedge-laying and celebrating his 70th birthday with tenants.
He took over management of the estate when he was 21 and says he hopes that in his time at the helm he has supported its people.
“I hope we can help support you a little bit, which is what I’ve been wanting to do all these years,” he says in the documentary.
The prince has been described by the Duchy of Cornwall’s keeper of records Alastair Martin as “very hands-on” in his role.
Mr Martin is also responsible for preparing the Duke of Cambridge, who will one day inherit the estate from his father.
Charles says his eldest son has had time to prepare himself for his responsibilities.
“He’s quite lucky because I found myself there at 21. I had a bit of baptism of fire really,” Charles says.
“He goes and visits different parts of the Duchy of Cornwall, and so he is learning, I hope, as time goes by.”
The Duke of Cambridge appears briefly in the first episode and said he has started to think about how he will inherit the duchy.
“Rest assured I’m not going to rock the boat. I’ll do much the same as what my father’s doing,” William says.
The documentary follows Charles to all corners of the estate, from family farms to the Isles of Scilly and his model village of Poundbury in Dorset.
Charles says the idea behind Poundbury was to build a community rather than “another housing estate” but acknowledges it was met with criticism. “Everybody was against it, and in the end I was determined to stick to my guns,” he says.
Farmers are the core of the duchy, with about 700 farming tenancies on the estate.