"Prince Charles really wants to save the world" – new BBC documentary spends a year with the man who will be king

The plantation was a riot of autumnal red and gold in late September as we filmed Prince Charles, his wife Camilla and her Jack Russell, Beth, for Thursday 15 November's observational BBC1 documentary.

• Prince Charles tells new BBC documentary he will not be as politically involved when he becomes King

“You can’t believe how much it’s grown,” said the Duchess of Cornwall. “It was tiny when it was all planted. The next thing you know, you’re being dwarfed by it!” But, after this dry summer, her husband is worried there hasn’t been enough water. “He does rain dances most of the day,” she joked, “to try and get some more!”

• The Crown: What was Prince Charles really like as young boy – and why did he hate his time at Gordonstoun?
• Discover the real history behind Netflix’s The Crown
• Everything you need to know about The Crown season three

The Prince is nursing another arboretum further south at Dumfries House in Ayrshire, the Palladian mansion he helped rescue in 2007.

Some of the trees there have not done so well in marshy soil, and he’s frustrated that they’re not growing faster. But the whole 2,000-acre estate has been growing rapidly. Outbuildings have been restored, and new ones erected, to house training and apprenticeships in textiles, catering, horticulture, engineering and stonemasonry.

The hope is to provide fresh opportunities in an ex-mining area of high unemployment, which was once the home of Keir Hardie, founder of the Labour Party. There’s a gym and sports centre for local people, who can use the estate freely, and the open-air swimming pool in the rundown town of New Cumnock nearby has been renovated and heated.

This ambitious project by the Prince’s Foundation at Dumfries House is the latest of his charitable ventures, which began 42 years ago with the launch of the Prince’s Trust. More than 900,000 young people have now been helped by it. “One of the things I’m most proud of my father for is the Prince’s Trust,” the Duke of Cambridge told us. “I think what he set up there for young people has been absolutely incredible, and as I go around the country the amount of people who tell me about the Prince’s Trust – I mean, honestly, it’s phenomenal, it really is.”

Both of Charles’s sons speak warmly about his commitment to the causes he has championed, and the ways they have learnt from him. “The man never stops,” says Prince Harry, who admires his father’s persistence with issues such as the environment, plastic waste and climate change. “Whether it’s dinner or tea or whatever and we sit there and speak to him, he gets so frustrated. You can understand why, when he cares that much and he’s been banging the drum for this long.”

We travelled with the Prince of Wales last November to three Caribbean islands wrecked by hurricanes two months before. He clambered gamely into a cramped seat in a tiny Britten-Norman Trislander plane (believed to be the last one still in service) to visit Barbuda. He flew on to Dominica, where not a single building escaped damage from the wind and floods, and picked his way through the rubble.

The amazingly cheerful people he met were clearly thrilled to see him. All the time he was listening and learning, in the attempt to help small island states improve their resilience to increasingly violent storms, which he believes are the direct result of climate change.

He was baffled at the way some people ignore scientific evidence in this area, “when they accept it in every other aspect of modern existence”. His wife admits that he is “pretty impatient”, but he is “driven by this passion inside him to really help. He really wants to save the world.”

Campaigning about climate change would be sufficient for most people. But the Prince’s list of passions – from red squirrels, Wagner and Shakespeare to community architecture, corporate social responsibility and a better understanding of Islam – is exhausting, not least because he involves himself in each one.

Some people have accused him of meddling in public affairs. His response is blunt: “If it’s meddling to worry about the inner cities as I did 40 years ago and what was happening or not happening there, the conditions in which people were living – if that’s meddling I’m very proud of it.”

When the time comes, Charles will be the best-prepared monarch in our history, and he will also bring decades of experience to the Commonwealth. On his visit to Dominica, he was accompanied by the British secretary of state for international development, Penny Mordaunt, who had been in office for little over a week.

In Australia earlier this year, the prime minister, Malcolm Turnbull, and the foreign minister, Julie Bishop, were at his side – yet four months later, both had left the scene. In the phrase made famous by Robin Day, they were “here today, gone tomorrow” politicians, whereas Prince Charles has been a constant. His use of that experience and longevity will be a major feature of the new reign.

In the Prince’s 70th year, the transition has begun. Last November, he laid the Queen’s wreath at the Cenotaph. On behalf of Her Majesty he opened the Commonwealth Games in April at a spectacular ceremony on Australia’s Gold Coast. Two weeks later he was confirmed as the Queen’s future successor as Head of the Commonwealth.

At the same time, his mission as Prince of Wales continues unabated. He works a seven-day week, starting at nine o’clock in the morning, and often finishing after midnight. Last year he had more than 500 business meetings behind the scenes, quite apart from his official engagements. He paces himself by going for walks, and makes a point of keeping his eyes open, whether counting the orchids in his wildflower meadow, or suddenly yanking a dead branch out of a tree, as he did (with surprising force) on his way to our filmed interview at Highgrove.

But the picture of the future monarch is becoming clearer. He is a man who is always stylishly and impeccably dressed, who has a proper sense of dignified ceremonial, yet can be more impishly relaxed than many people realise. An off-the-cuff short speech to the citizens of Bundaberg in Queensland (no script, no notes) was remarkable for its blend of spontaneity, wit and warmth, while an address to thousands of Pacific islanders in Vanuatu displayed a thespian sense of timing, and a delight in speaking pidgin. It must have been maddening to have a film crew following him for almost 12 months, but without fail he was good-humouredly gracious.

Back home, following Charles on a visit to Durham earlier this year, the big surprise to me was seeing the hundreds of young people lining the route. Prince Charles had arrived on the royal train on a crisp, sunny February morning, and the crowds were out in force. It was instructive to watch his easy informality in pressing the flesh, as he found in each fleeting encounter a personal connection or a shared experience. But I hadn’t expected so many students to turn up, and to be so excited. The reason was clear, as one of them explained: “We’ve come to see our future king.”

Prince, Son and Heir: Charles at 70 on Thursday 15 November at 9.00pm on BBC1

This article was originally published on 8 November 2018