Prince Charles said he will stop "meddling" in public affairs when he becomes king, telling a BBC documentary crew his role as sovereign would be very different to his life as heir to the throne.
The prince, who will turn 70 on November 14, has been an active campaigner for causes such as wildlife conversation and climate change.
As he is not bound by the constraints imposed on his monarch mother, Prince Charles believes he can speak his mind freely, but tries to remain bipartisan.
In an interview with filmmaker John Bridcut, said he was proud of his "meddling" and explained it as the way his historical role of Prince of Wales translated in a modern world.
"Each one of my predecessors had to find out how they were going to do it — a lot of them dropped dead or were killed before they got very far," he said.
"The Black Prince was the first one and he rushed about doing all the complicated bits, fighting battles while his father sat somewhere else.
"So really, he was busy winning his spurs and, in a sense, that's still what has to happen I think."
Campaigning for a cause
He said he was encouraged by politicians to take an interest in public affairs and believed people would have been "rather fed up" if he hadn't.
But he will accept the responsibilities and the limitations the role of sovereign will bestow on him.
When asked if his campaigning would continue when he became king, Prince Charles was adamant in his response.
"No it won't," he said.
"I'm not that stupid."
He said he would "operate within the constitutional parameters" of being the head of the monarchy.
"If you become the sovereign, you play the role in the way that it is expected," he said.
"It's a different function."
Bridcut and his film crew followed Prince Charles for a year, also interviewing the Duchess of Cornwall and Prince Charles's two sons, the Dukes of Cambridge and Sussex, for the hour-long documentary.
The film, called Prince, Son and Heir: Charles at 70, aired yesterday on the BBC in the UK on Thursday (local time).
