The real Charles revealed: William's wild mood swings, Harry's pre-wedding meltdown and how the Prince of Wales finally earned his boys' respect, as revealed by his biographer. Photo / Getty
For Prince Charles's official 70th birthday celebrations at Buckingham Palace in May, it was his younger son Harry — just three days after his wedding to Meghan Markle — who marked the occasion with a speech of self-deprecation and rare warmth towards his father.
"Pa," he said, "while I know you've asked that today not be about you, you must forgive me if I don't listen to you. Much like when I was younger. Instead, I ask everyone here to say a huge thank-you to you, for your incredible work over nearly 50 years."
He went on: "It is your selfless drive to effect change, whether that is to improve the lives of those who are on the wrong path or a particular species under threat, which William and I draw inspiration from every day."
The speech was heartfelt, sincere and funny. Occasionally, however, the level of belligerence Charles has encountered from his sons has shocked the Prince, as both boys have, on occasion, challenged him.
William has even been known to speak firmly in his father's face. It is reminiscent of his mother's hot temper, which Charles had to deal with on a frequent basis during their marriage.
He could not attend the celebrations as he was away on official duties to mark the anniversary of the Manchester Arena terror attack. But subsequently, he approached Charles's top aide, Clive Alderton, making it clear that he'd like to do more joint engagements with his father in his 70th birthday year.
William may be Charles's heir, but he's extremely competitive with members of his family when it comes to media coverage — although he gives the impression it doesn't concern him.
In reality, it does. Take Meghan and Harry's appearance in Cardiff on a royal engagement in January.
It was a time of peak interest in the couple. Intriguingly, William — who was also on a royal engagement — chose the same day to display a new and dramatic buzz cut hairstyle. As a result, Harry was not the only royal prince featured in the following day's papers.
The two brothers get along well most of the time. William was happy, for instance, for Harry to pursue his passion for helping injured servicemen by setting up the Invictus Games.
As far as William is concerned, Harry is aware that his brother is Number One in the royal pecking order.
Many members of staff, even operators on the Palace switchboard, are aware that William can be 'difficult' or 'a little grand'.
Indeed, even Charles is said to be wary of his mood swings. In the years immediately after Prince George's birth, William notably preferred to focus on his young family rather than spend time with his father at either Highgrove or in London.
Since then, there's been a froideur between William's court and that of Charles.
So it was a little surprising that among the pictures on display for his 70th birthday exhibition at the Palace — entitled Prince & Patron, for which the Prince loaned out his favourite artwork, trinkets and family photos to help present a glimpse of his home life — was a never-before-seen photograph of him cradling his first grandson, George, with his elder son the Duke of Cambridge by his side.
Displaying the photograph in public would have required the Duke's permission. "Ha, perhaps William is mellowing," said an inside source.
Harry, while also prone to volatility, is a much warmer man than William — and is far more given to emotional outbursts. Like his mother, he tends to wear his heart on his sleeve.
During the build-up to his marriage to Meghan — and indeed beyond — insiders noticed a change in his relationship with his father: he'd begun to show him much more respect than he had previously. After all, Charles had not only bankrolled the wedding but done everything he could to ensure that it went smoothly.
On the day itself, Meghan managed to look remarkably relaxed, despite knowing that her every move was being tracked by TV cameras for the benefit of more than a billion viewers. But Prince Harry was unable to hide the state of his nerves.
The first sign of this came just after Charles, in the absence of Meghan's father, had walked her up the aisle.
As Harry whispered "Thanks, Pa," he was almost shaking with tension the weeks leading up to the wedding had been far more tense for both Harry and Meghan than most people realised.
In fact, they'd both felt so stressed that they'd booked a series of appointments with Ross Barr, known as "the acupuncturist to the stars".
Whether these treatments had much impact on Harry is debatable. In the build-up to the wedding, says an inside source, he was "petulant and short-tempered" with members of staff.
Raising his voice on occasion, Harry would insist: "What Meghan wants, she gets."
The Prince of Wales is a stickler for showing deference to the Queen and her office, and in my extensive talks with people close to Prince Charles, I've been assured that Harry and his brother have always shown appropriate deference to their grandmother.
William has total respect for the Queen. When she talks, he listens. She is the one person, perhaps with the exception of his wife, Catherine, who is able to pull him in line with a quiet word.
Indeed, it was she who made it clear to both him and his brother that their noble Heads Together mental health campaign appeared too separate from the rest of the Royal Family and the traditional type of engagements expected of the family.
Insiders say, however, that Harry and William have by no means always shown proper respect to the Prince of Wales and his office.
To this day, Charles admits he often finds it difficult to gauge either of his sons' occasionally unpredictable moods. 'In that aspect of their nature, both princes are very much like their mother,' one close source confirmed.
A former courtier made the same analogy. "They both have quite extreme mood swings, just as Diana did," he said. "She could be your best friend one minute and the next your worst enemy."
But if William and Harry have at times had a difficult relationship with their father, it's not all that hard to understand why.
Both boys blame Charles for being absent through much of their childhood — he was often working or away on business.
And when he was around, he was neither a stern disciplinarian nor a rough-and-tumble father.
Diana, meanwhile, allowed Harry and William to run free and wild. One departing police protection officer even remarked to his replacement: "Good luck, you're going to need it. If those kids were brought up on a council estate somewhere in South London, they'd have been taken into care by now." He was deadly serious.
At Highgrove, the brothers would relieve themselves from the top of a giant haystack in the garden, much to the annoyance of their 'papa', who occasionally caught them in the act.
On one occasion, Harry burrowed into the haystack and was soon struggling for breath. He was in some distress when a policeman found him — just in time.
Harry was usually the naughtiest of the two. His nanny, Jessie Webb, frequently sandwiched the little prince up against the wall, saying it was the only way she could catch him and 'gain control'.
One hot summer's day, he caused a major ruckus when he disappeared again. Looking for somewhere cool, he'd crawled into one of Charles's giant urns — where he'd been unable to hear the increasingly desperate calls from his parents and their staff.
After their parents' marriage imploded, the boys saw even less of their father. A further source of tension was their perception of how he treated their mother, whose tears they often had to witness.
Somewhere in the mix, too, is their confused relationship with Camilla Parker Bowles, whom their mother loathed with a passion and famously accused of being the third person in her marriage.
Even years later, when Charles finally married Camilla, the brothers' mood was privately more one of acceptance than of undiluted joy at the prospect of having her as a stepmother.
After Diana's death, their father had done his best to provide them with love and security, though it's hardly a secret that William, then 15, and Harry, nearly 13, had a difficult adolescence.
Charles, by giving them so much freedom and independence that he himself had not been afforded as a young man, has in effect allowed them to develop their own ideas and interests, but also a streak of defiance. 'HRH has changed things unbelievably for his sons — and to their advantage,' one former courtier said.
"A decade or so ago, before he married the Duchess, the Prince gave them their own court that he personally funds. He did this in spite of the fact that for his own staff, it proved more difficult because they effectively lost control of the boys.
"But the Boss wanted his sons to have their own staff so that they would not be puppets run and controlled by his office.'
It IS Meghan's own relationship with Charles that is proving to be key to newfound warmth between him and his second son.
"When Meghan met the Prince of Wales, she was bowled over by his gentlemanly charm," said an inside source.
"She told Prince Harry he was wonderful; welcoming, warm, hard-working, kind and stable. She made it clear that he should appreciate him and bond more." She consulted him about the music for the wedding, while Charles has taken time to discuss with her the intricacies of life in the 'Firm'.
It helps that Meghan is fascinated by British history, and royal history in particular — far more so than her husband. Sources say she has been poring over lever arch files of notes about the Commonwealth. Whenever she's confused, she always turns to Charles, and he takes time to explain the complexities.
True, she's made the odd slip-up. This year, for example, when Charles invited her to join him and Camilla on a private tour of an exhibition he'd curated at the Palace, Meghan enthusiastically accepted. But when her advisers told her there would also be a documentary crew present, she belatedly pulled out.
Cancelling on Prince Charles after one has accepted his invitation is not the done thing.
He sees his work ethic and his passion for philanthropy reflected in his new daughter-in-law, who has campaigned in the past to raise awareness of women's issues. Nor will it have escaped his notice that she shares Charles's belief in the importance of organic food.
Camilla, meanwhile, has played her part as a sort of 'super-granny', dispensing humorous, down-to-earth advice to Meghan. It is understood the two 'outsiders' have become close in a short space of time, and they were seen clasping hands as they greeted one another at the Palace.
As for Prince Charles, he has been utterly charmed by the beautiful actress.