It's no secret that Prince Charles's relationship with his sons Prince William and Prince Harry has had its ups and downs. It hasn't always been straightforward and easy, especially after Harry chose to step back from royal life.
SEE: 14 photos that prove Prince Charles is a doting grandfather
The Duke and Duchess of Sussex made the effort to return to the UK to celebrate the Queen's Platinum Jubilee earlier this month, although they kept a very low profile and were hardly seen interacting with Charles.
While tension may still exist between Charles and his younger son, his bond with his eldest and the future King, William, has remained strong. Even before the royal family's rifts and troubles came to light, William always had a nice word or two to say about his dad. Take a look at what William has said in the past…
WATCH: Prince Charles can't control his laughter at Platinum Jubilee
Prince Charles is committed to his sense of duty
Both Charles and William will one day be King, something that will always bring them together especially after William welcomed children of his own, knowing that Prince George will follow the same path. The Prince of Wales and the Duke of Cambridge have a shared bond over their sense of commitment to duty and service.
SEE: 16 photos that show Prince Charles' fatherly bond with William and Harry
READ: Camilla borrowed Prince Charles' clothes for Jubilee appearance and no one noticed
The Cambridges always have a laugh with Prince Charles and Camilla
William has previously spoken about how disciplined and how much of a workaholic Charles is. To mark the Prince's milestone 70th birthday, the BBC released a documentary, Prince, Son and Heir: Charles at 70, where they interviewed family members and those closest to Charles.
"He has amazing personal discipline," William said in the documentary. "So, he has – and it's frustrated me in the past a lot – he has a routine. The only way to fit all this stuff in is things have to be compartmentalised. The man never stops. I mean when we were kids there was bags and bags and bags of work that the office just sent to him. We could barely even get to his desk to say goodnight to him."
Prince Charles is determined to get the job done
In the same documentary, William was asked whether he had a birthday message for his father. He replied: "I'm very pleased that he's made 70. You know if you ask him if the job's done, it's not.
READ: Prince Charles talks 'bickering' at Jubilee celebrations amid royal reunion
"I'd like to see his passions and his interests and the things he's been campaigning for come to fruition completely for him," said William
"But more than anything I'd like to see his passions and his interests and the things he's been campaigning for come to fruition completely for him. He hasn't even reached the point that his natural progression should do – i.e. being monarch. So, you know he's still got his job to do."
Prince Charles can be an embarrassing dad
It's hard enough having the future King as your dad, but William and Harry have previously opened up about cringe-worthy moments as children. During ITV documentary When Ant And Dec Met The Prince: 40 Years Of The Prince's Trust, William reminisced on how Charles had a habit of "rabbiting on" and would laugh at all the wrong moments.
"I was in some sort of Christmas play and I was a wizard and I came on and I narrated it," William reminisced. "There was meant to be a bit of pyrotechnic explosion in front of me and I jumped on stage and nothing happened, and so I started reading it and of course at this point I was quite panicky and then the pyrotechnic went off as I was reading.
"I was like 'Er…' and literally he couldn't stop laughing the whole way through the production and so several times I'd stop, I'd cast an eye across, a big death stare, and then I'd try and get back to my lines. It was terrible. Honestly."
Charles could often be an embarrassing dad
Prince Charles kept in touch with his sons through letter-writing
When William and Harry were away at boarding school in Eton, he kept in touch with them by writing letters. Although, the brothers have joked about his "spider-like" handwriting.
"His writing in his letters is notoriously difficult to read but as it gets later in the evening, it's about 12 when he's writing letters, we can tell instantly. When he's falling asleep you get these long sort of A's that disappear off the page," William said on ITV's When Ant And Dec Met The Prince: 40 Years Of The Prince's Trust.
The Duke added that he and Harry would swap letters and read each other's, just to make sure they weren't being told off and they didn't realise it.
William said his dad is "brilliant" with the kids
Prince Charles is a 'brilliant' grandfather
Appearing on Prince, Son and Heir: Charles at 70, William described his dad as being a "brilliant" grandfather, although he wished he could spend more time with his grandchildren.
On whether Charles has time to be a granddad, the Duke said: "It's something I'm working more heavily on, put it that way. I think he does have time for it, but I would like him to have more time with the children.
"I think he's… now he's reached his 70th year it's a perfect time to consolidate a little bit because as most families would do, you are worried about having them around and making sure their health's okay. And he's the fittest man I know but equally I want him to be fit until he's 95. So, having more time with him at home would be lovely, and being able to you know, play with the grandchildren. Because when he's there, he's brilliant. But we need him there as much as possible."
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