How the King went from being dubbed ‘a bit of a hippy’, to hosting A-list celebrities at his own film premiere… and showing off ‘Cluckingham Palace’: ROBERT HARDMAN

He has been attending royal film premieres all his adult life but, until tonight, the King had never hosted one at home. 

Windsor Castle’s Waterloo Chamber had been transformed into a very grand cinema with plenty of royalty and a very respectable A-list celebrity turnout too – including Dame Judi Dench, Kate Winslet and Sir Rod Stewart. 

The clue was in the title of the film: ‘Finding Harmony – A King’s Vision’ – and the deep green colour of Queen Camilla’s Anna Valentine dress.

The monarch was not just starring in this production but he was, in effect, the scriptwriter and producer too.

Ahead of tonight’s screening and black tie reception in St George’s Hall, the invited guests heard Ms Winslet – who is the film’s narrator – salute the King for his ‘great vision and foresight in protecting our natural world’.

For this is really a 90-minute documentary about the guiding principle behind the King’s life and work, as both Prince and monarch: we are part of nature, not apart from it.

That, we are told, is the essence of ‘harmony’. As Prince of Wales, he wrote a book of the same title in 2010 – it is about to be republished – and now we have the film version.

Viewers will see a side of the man which has been largely eclipsed since his accession to the throne – Charles, the eco-warrior, activist and outspoken critic of ugly buildings, filthy factories and deforestation.

They will also hear him pay tribute to his grandmother, Queen Elizabeth the Queen Mother, for opening his eyes to the natural world while his friends call him ‘a bit of a hippy’ who was deeply upset by all the mockery which was once heaped upon him for talking to his plants.

No doubt there will be much amusement over a scene where he is gathering eggs from the Highgrove hen coop which he calls ‘Cluckingham Palace’, or another where it all goes a bit Dr Who during a whizz through the galaxy while the King murmurs: ‘We are a microcosm of the microcosm’.

It is certainly a very different sort of royal documentary from the sort we are used to, not least because it will not be on terrestrial television. 

Rather it will be broadcast simultaneously to 240 territories through the streaming giant, Amazon, from next Friday. 

It has also been made in conjunction with the King’s Foundation, the charity which Prince Charles created in his activist days to ‘create sustainable communities’. It is, therefore, a polemic rather than an objective study. 

Some may find it preachy (and it does include a couple of preachers, as well as the King’s private chapel at the bottom of the garden). 

However, it also features plenty of humour, some clips from the Royal Family’s private cine archive and some spectacular photography.

It is also a reminder of just how far the young Charles was prepared to stick his neck out when he felt that scientific progress was moving too far and too fast for the benefit of mankind. 

It is striking how prescient so much of it was – from the ghastliness of so much post-war urban redesign to the dangers of filling our rivers with industrial waste.

By all accounts, the King thoroughly enjoyed making it. The production team – which included his own King’s Foundation – told me that he was so carried away during one monologue as he strolled through his garden that he walked straight into a branch.

Ultimately, he says towards the end, we have to follow ‘the underlying principles behind what I call harmony if this poor old planet is going to support so many of us.’ He adds ruefully: ‘It’s unlikely there’s anywhere else.’

At least there was no need for a red carpet at tonight’s premiere. Windsor Castle has quite enough of the stuff already.

– In Saturday’s Weekend magazine… King Charles, our monarch on a mission and why he wants us all to live in perfect Harmony.