"Eventually people might realize that some of the things I've been trying to do aren't all that mad" Prince Charles

He has reached the age at which most people retire. Yet at age 60, Prince Charles is still waiting to undertake the role for which he was born and is now the longest-serving monarch-in-waiting in British history. For a year the BBC television documentary Charles: The Passionate Prince was granted unprecedented access and allowed to film the Prince of Wales at home, abroad, at work and on duty. The result is an intimate portrait of the private and passionate man behind the controversy and the headlines, offering insight into some of the issues close to his heart.

He could, as he said in the documentary have sat back and done very little other than enjoy the immense privileges and almost unlimited pleasures to which a Prince of Wales is privy. But Prince Charles has defied convention to become, and at age 60 has become one of Britain's most outspoken and prolific campaigners, as well as being a businessman, ambassador for Britain and a father.

He is asked in the documentary whether, as King, he would still "champion big themes". Charles answered: "I don't know. I don't know - probably not in the same way. But I like to think perhaps that after all this, eventually people might realize that some of the things I've been trying to do aren't all that mad and that I might have some 'convening power' that could be put to use." This revealing film goes behind the closed doors of the Prince's world and gives us the chance to make up our own minds about the man who may one day be king.

Produced for the BBC, Nick Vaughan-Barratt, is the programme's executive producer.