‘She was a total kid. I can still hear that crazy laugh ...and see the pure happiness on her face’

TO THE public, Diana played many roles from the ‘People’s Princess’ to style icon and tireless charity champion. But to her sons she was simply a loving mum with a great sense of fun and adventure, or as Harry succinctly puts it: ‘A total kid, through and through.’

Had she lived, she would now be mischievous ‘Granny Diana’ to William’s children, George and Charlotte. And, he thinks, probably ‘an absolute nightmare’ at bath time as he and Kate struggled to keep order.

In the film, Harry warmly recalls how much Diana valued the chance to escape the limelight and just spend time with her two boys.

‘My mother cherished those moments of privacy and being able to be that mother rather than the Princess of Wales,’ he says. ‘She made the decision that, no matter what, despite all of the difficulties of growing up in that limelight and on that stage, she was going to ensure that both of us had as normal a life as possible.’

Yet despite their gilded childhoods of immense privilege, it is notable that it is the simplest of things which rekindle the boys’ fondest memories as they leaf through photographs sitting in Kensington Palace, a place where they spent many of their happiest times.

One of their favourite haunts was Thorpe Park resort in Surrey, where they and

WILLIAM ON HER HUMOUR She sent me the rudest cards... I dared not open them in class

their mother giggled helplessly as they were famously drenched, careering down the Logger’s Leap water flume in 1993.

Though that trip was covered by the media, they had previously made two private visits, away from the cameras.

Harry clearly still relishes those private moments of fun: ‘If that means taking us for a burger every now and then or sneaking us into the cinema, driving through the country lanes with the roof down, listening to Enya, I think it was – a blast from the past! – all of that was part of her being a mum.

‘I think she lived a lot of her life, especially in private, through us. And I think that sort of childish fun element really came out when she was spending time with us.

‘Our mother was a total kid through-and-through. When everybody says to me, “so she was fun, give us an example”… all I can hear is her laugh in my head. And that sort of crazy laugh where there was just pure happiness on her face.’

It will come as no surprise to many that Diana delighted in defying rules and convention.

‘She was one of the naughtiest parents… One of her mottos to me was, “You can be as naughty as you want, just don’t get caught”,’ says Harry.

‘She would come and watch us play football and smuggle sweets into our socks.’

He recalls ‘walking back from a football match and [hiding] five packets of Starburst... the whole shirt was just bulging with sweets, and then look around, open the tuck box, throw it all in, lock it up.

‘Behind closed doors she was a very loving caring mother, and an incredibly funny person.’

William ruefully recalls how his mother would delight in sending him risqué greetings cards at school – so much so that he always opened them in private.

‘She was a massive card writer. She loved the rudest cards you can imagine,’ he says

‘I would be at school and I’d get a card from my mother. Usually she found something very embarrassing – you know, a very funny card and then wrote very nice stuff inside. But I dared not open it in case the teachers or anyone else in the class saw it.

‘There was always a sense of enthusiasm and energy around her, and a lot of warmth as well.

‘There was always that sort of… bubbling personality going on the whole time.

‘She had a very cheeky sense of humour. She was very jolly and really enjoyed her times making a lot of mischief.’

One of the most astonishing tricks which Diana played on her elder son famously involved three supermodels.

‘There are a couple of memories that I have that are particularly funny,’ recalls William. ‘Just outside the room where we are now [in Kensington Palace], she organised, when I came home from school, to have Cindy Crawford, Christy Turlington and Naomi Campbell waiting at the top of the stairs.

‘I was probably a 12 or 13-year-old boy who had posters of them on his wall and I went bright red and

didn’t quite know what to say and sort of fumbled, and I think pretty much fell down the stairs.

‘I was completely and utterly awestruck. But that was a very funny memory that’s lived with me for ever about her – loving, embarrassing and being the joker.’

William says his own approach to parenting comes from his mother’s hands-on approach, which broke the traditional mould for royal children. And he says the most important message he takes from his mother is the importance of those first few years.

‘I want to make as much time and effort with George and Charlotte as I can because I realise that these early years particularly are crucial for children, and having seen, you know, what she did for us…’

And he pays tribute to her humanity, and ability to form an instant rapport with whoever she met.

‘That immediate warmth was always there for whoever she met.

‘It didn’t matter where you came from, what you did, you know, she could talk to you. And I think she generally just had a real ability to connect very quickly.’

While Diana’s rebellious streak instilled a streak of fun in the boys, she also made them aware of their responsibility to look beyond their pampered existence and take an interest in those who are less fortunate.

William says: ‘She was very informal and really enjoyed the laughter and the fun. But she understood there was a life outside of palace walls and she wanted us to see it from a very young age.

‘And we understood some of the real, real problems in life that can pass you by very easily, particularly in this situation, if you don’t go looking for them.’