In his memoir, the Duke of Sussex remembers the King as a distant and inadequate father – but these recollections could not be further from Dame Penny Mordaunt's memories of Charles.
While Prince Harry, 42, wrote that the monarch had 'trouble being intimate face-to-face' in Spare, Dame Penny said Charles epitomised the doting grandfather in a starkly different account of the man behind the Crown.
Speaking at Cheltenham Literature Festival, the former defence secretary, 53, recalled how King Charles was 'bored out of his mind' during rehearsals for his Coronation ceremony – until a surprise visit from his cheeky grandson.
The King 'sprung to life' at the sight of Louis and immediately halted rehearsals so he could show Prince William and Kate's youngest child the Crown Jewels, Dame Penny told the crowds.
Prince Harry's Spare, by contrast, paints a very different picture of Charles. 'Pa didn't hug me,' he wrote, recalling they 'mostly co-existed' after his mother, the late Princess Diana died.
But Dame Penny isn't the only person who has recently testified to Charles's 'hugely affectionate' nature as according to the Daily Mail's columnist Nadine Dorries 'love leapt from the King's eyes' for Prince William, as she reported how much they enjoyed each other's company.
In his book Spare, the Duke of Sussex claimed his father, King Charles, wasn't the most emotionally present parent - but others have indicated differently (pictured with the Prince of Wales in Kensington Palace in 1985)
Prince Louis pictured sitting on his grandfather's lap at the late Queen's Platinum Jubilee celebrations in 2022
'I once had the honour of spending time alone with the nuclear Royal Family, and I was struck by what a normal bunch they are in how they interact – full of banter,' she wrote. 'They are also hugely affectionate towards each other.
'I’m not exaggerating when I say that love leapt from the King’s eyes as he and Prince William took the mickey out of each other, just like any father and son.'
Now, cast your mind back to Prince Harry's controversial memoir that was released over three years ago as he remembered his 'Pa' as being 'checked out' and ill-equipped to handle the demands of being a single parent.
'Not that Pa hadn't always been a bit checked out,' one passage read. 'He'd always given an air of being not quite ready for parenthood - the responsibilities, the patience, the time.
'Even he, though a proud man, would've admitted as much. But single parenthood? Pa was never made for that.'
Another section read: 'Pa and I mostly co-existed. He had trouble communicating, trouble listening, trouble being intimate face-to-face.
'On occasion, after a long multi-course dinner, I'd walk upstairs and find a letter on my pillow.
'The letter would say how proud he was of me for something I'd done or accomplished. I'd smile, place it under my pillow, but also wonder why he hadn't said this moments ago, while seated directly across from me.'
It is hard to reconcile this version of Charles with Dame Penny's portrayal, as she told Cheltenham Literature Festival how he lit up around Prince Louis.
Dame Penny – who was Lord President of the Privy Council – attended Coronation proceedings as part of her role in carrying the ceremonial Sword of State during the ceremony, held on May 6, 2023.
She said Prince Louis's surprise visit to Westminster Abbey during rehearsals is a memory she will 'treasure'.
Harry and his father Charles pictured at a photocall at Highgrove in 1999
William, Charles and Harry pictured looking at an iPhone as they watch the athletics during the Invictus Games at the Lee Valley Athletics Centre in 2014
Dame Penny said: 'We were doing dress rehearsals on the Thursday before, and the King was bored out of his mind. He'd just done two weeks of this, and he'd had enough. I was watching him glaze over in the coronation chair.
'And then he suddenly sprung to life because beside him was Prince Louis, who had come to visit. They stopped the rehearsal so that he could show Prince Louis all the Crown Jewels. That's a memory that I shall treasure.'
The former defence secretary isn’t the only person whose account of Charles, the father, varies from Prince Harry’s unflattering portrayal in Spare.
Prince Edward’s ex-girlfriend Ruthie Henshall also gave a different account of Charles’s parenting style in her sensational book, The Showgirl And The Prince.
'I watched Charles playing rough and tumble with William and Harry (then aged ten and eight) in the Balmoral corridors. He clearly loved those boys, and they were squealing with joy as daddy chased them.'
Even Penny Junor’s recollections about Charles vary from those of his younger son; the British journalist recalled how William and Harry would launch themselves into their father’s arms after time away from him.
Writing in her book, Charles: Victim Or Villain, Ms Junor wrote: 'Whenever Charles arrived at home at Highgrove by helicopter, it would land on the front field, where sheep graze.
'As soon as William and Harry heard it overhead, they would come running out to meet him.
'Once it landed safely, they would race across the field and jump into his arms for a hug, smearing one suit after another with the sheep droppings they had trodden in on the way.'
She explained elsewhere in the book: 'The Prince's private persona is also completely different from his public one. He fools around with the boys, they tease each other, laugh, joke, rough and tumble, and even hug and kiss.'
Ms Junor recalled how Prince Harry ‘smothered his face in kisses’ during their 1997 skiing holiday in Klosters in the middle of a formal dinner party.
'On the last night of their skiing holiday in Klosters in 1997, there was a big farewell dinner party in their hotel restaurant.
'In the middle of dinner, Harry got to his feet and, in front of a table full of people, made a little speech to thank Papa, as both boys call him, for giving him such a wonderful holiday.
'He then walked up to his father and smothered his face in kisses until, in mock embarrassment, Charles begged for mercy. It was a touching scene.'
Royal author Christopher Andersen is of a similar opinion as Ms Junor, writing in Brothers And Wives: Inside The Private Lives Of William, Kate, Harry, And Meghan: 'The public simply never got to see Charles's interactions with William and Harry, or the undisputed depth of affection between father and sons.
'The game of Big Bad Wolf that sent the boys into hysterics as they tried to frantically escape their huffing and puffing dad, the fierce pillow fights that churned up massive clouds of feathers, the wrestling matches and tickle fights.
'Even the days spent fishing in the Scottish countryside and the long walks at Sandringham with Tigger and Roo - all took place far from the prying lenses of the indefatigable paparazzi.'