The 73-year-old grandfather, who has been heir apparent since he was three years old, is now finally fulfilling his destiny, with his coronation due at Westminster Abbey on 6 May (with a new bank holiday falling on 8 May).
Known for his charitable endeavours – most notably his efforts around supporting youths with The Prince’s Trust – Charles is a staunch climate crusader.
But what’s he really like as a person and will he make a good monarch for years to come? We look to the celebrities and well-known figures who have spent time with him and provided insight into his character.
From one old leader to a new one, former prime minister Gordon Brown expressed the high hopes and expectations he has for the new monarch.
"Do not imagine for an instant that in the long years past he has not watched, absorbed and thought about what it means to be King," the 71-year-old noted after Elizabeth II’s death, according to Country Life. "He is well prepared and, I have no doubt, resilient for the task ahead."
Dame Judi Dench, 87, who backed the Countryfile Plant Britain campaign with Charles in 2020, and has met him a number of times, sees his artistic side and love of the outdoors as great qualities to have.
"What struck me when we met was his passion for painting (he really is quite a remarkable painter), his love of walking, for trees, the countryside and Cornwall — everything I also feel so deeply about," Country Life also reports the actor said.
Netflix recently added a disclaimer to The Crown trailer after criticism from Dench herself.
Furniture restorer and presenter Jay Blades, 52, said the experience of meeting Charles for the special episode of his BBC show The Repair Shop, which aired last month, was "really unbelievable".
The pair, alongside a team of expert craftspeople, explored their shared passion for preserving heritage craft skills.
"Working with King Charles, well he was the Prince of Wales then and now King Charles III, I couldn't believe that someone from a council estate and someone from a royal estate... we just got on like a house on fire," Blades told PA news agency on this year's National Television Awards' (NTAs) red carpet.
"As Will said the other day, 'I thought you and him knew each other from years ago, the way you guys were speaking to each other.'
"You're going to see the prince then and the King now in a way that you've never seen him – he is so relaxed, to the extent where the protocols are kind of out the window. We talk to each other, we're laughing, we're just having a great time."
Margolyes, 81, revealed in her memoir, This Much is True, that she feels "very protective" about Charles.
“We have met a handful of times over the years but I was amazed when Lindy my agent rang me to say, ‘Prince Charles has invited you to go and spend three nights in a house party in Sandringham,'" she wrote.
Describing her visit, which included swimming with Camilla, she described the King and Queen Consort as “cracking good hosts”.
Margolyes and her fellow guests, which included David Hockney and Stephen Fry, were entertained by Charles performing a monologue written by Barry Humphries. “The prince is a fine actor, he had a superb Aussie accent and he made us all laugh,” she recalled.
She added, “I think he’s a good man who cares a great deal for the country, and I can’t bear the horrid things people write about him and the other members of the Royal Family.”
Rock star Rod Stewart, 77, is thought to be a close friend of the King. He was previously an ambassador for The Prince’s Trust and performed at his 60th birthday in addition to the Queen’s Platinum Jubilee celebrations earlier this year.
During a BBC Breakfast interview, when Naga Munchetty asked who he thought was most likely to get up and dance out of the royals at the Jubilee, he responded, “Umm, Charles” explaining this was his answer, “because I love him, and my wife absolutely adores him”.
“She [the late Queen] has been so much a part of my life she’s almost like a sister, she has always been in the background," he added.
Richard E. Grant
In his memoir, actor Richard E. Grant, 65, praised the King for the kindness shown to his wife before her death from lung cancer last September.
Grant explains that he and Camilla sent long, solicitous letters and arranged a visit to Highgrove House around Washington’s medical appointments.
He told the Mail on Sunday’s You magazine, “He’s a well-documented fan of accents and The Goon Show, and as my wife was an accent coach he loved her ability to do different voices.”
“They were both extraordinarily kind, visiting and so on, given how busy he is,” added Grant.
Ainsley Harriott, 65, said he and Charles “ended up having a right old giggle” when Harriott was awarded an MBE in 2020 for his services to broadcasting and culinary arts.
“He was telling me he used to watch my TV shows with his children, then we were nattering about growing herbs,” the chef told the iPaper last September.
“He’s a really keen gardener and he knows what he’s talking about.”
Welsh actor and singer Luke Evans, 43, this week spoke of the new monarch’s natural ability to “find a common ground” with whoever he talks to.
“He’s an honorary Welshman to us too, and has been a wonderful representative of our country,” Evans told Good Morning Britain in September.
Evans narrated ITV’s 2019 programme Charles: 50 Years A Prince and said that his work as an ambassador for The Prince’s Trust has enabled him to meet the King “several times” over the last decade. “It’s always been a very enjoyable experience I have to say,” he added.
“I think that’s one thing you notice when you’re with King Charles: his company. It doesn’t matter what walk of life you’re from, what age you are, he finds a common ground, and makes you feel that you deserve to be there.”
TV star Carol Vorderman, 61, shared a heart-felt tribute for the new King on her Instagram in September.
She praised him for championing environmental issues and young people “decades before it became popular” and believes “he will become a great King”.
Vorderman is an ambassador for The Prince’s Trust and said she has met the King and Queen Consort many times.
Sharing a series of images of Charles, the Trust’s logo, and her encounters with the monarch, she wrote in part: "Long Live The King
"I wish King Charles every element of peace, joy and strength during his reign. I believe he will become a great King. For decades before it became popular, he has championed environmental issues and young people.
“One thing I know beyond any doubt whatsoever is that King Charles believes that no matter your background, no matter your story so far, there is goodness and a hope within us all,” she added.
She said she has "only words of respect and love towards [Charles and Camilla]."
Sir Trevor McDonald
Sir Trevor McDonald, 83, knighted for his services to journalism in 1999, interviewed Prince Charles in 2006 for the documentary The Prince of Wales: Up Close.
He told ITV’s Good Morning Britain, speaking on the new monarch, “In a way, we are terribly fortunate at this time to have someone who took part in a conversation that is now universally recognised as very important about the planet in which we all live.
“We know there is a King on the throne who has led this conversation, who has a deep understanding of all the issues involved and I think that is matter of great good fortune for our country and for the Commonwealth.
“I was fortunate enough to do a documentary about him and his duties in the family and he said, ‘You know I am probably a little misrepresented at times.’
“What I remember about it is he said, ‘What people don’t understand is that I have a profound love for this country and I would do my duty’ and that is what we have seen in glorious colour. He will be a great King.”
On what we might expect from Charles, he added, “I think his profound love and respect for the job, and respect of what his mother Queen Elizabeth did, will guide him through.
“He will take a very practical approach to some of these problems and he will be the great encourager, he will want to talk to people involved.”
Sir Ben Kingsley
Oscar-winning actor Sir Ben Kingsley, 78, only had positive things to say about the King during the 40th anniversary of The Prince’s Trust in 2016.
“I think he’s a very unique combination of enormous compassion, without ego – it’s a very rare combination," he said.
As someone who has been an ambassador himself, he also spoke of the charity's benefits. “It’s not throwing money at the problem, it’s throwing intelligence and care and affection, and I think at the centre of it is HRH’s [His Royal Highness] profound affection for what he does and the people for whom he does it."
The Trust grew from Charles’ concern that young people were being excluded from society through a lack of opportunity. He used his severance pay when leaving the Royal Navy to fund a number of community schemes, marking its early initiatives
Additional reporting PA.
Watch: King Charles vows to serve with 'loyalty, respect and love' in first address to nation