'I knew Prince William, Kate and Harry - we have to accept brutal truth about rift'

Effortlessly beautiful, her natural elegance matched only by her obvious intelligence, Kate Middleton was just 22, but royal butler Grant Harold knew she was a “queen in waiting.”

One of King Charles ’ trusted butlers for seven years - spent mainly at Highgrove - he is uniquely placed to reveal what really goes on behind the palace gates.

He tells The Mirror : “That girl was a Queen in waiting in every aspect. She is the perfect Queen material and you can so obviously see that. Everything about her - the way she carried herself, the way she spoke, the way she interacted with people, her kindness, her beauty - she was, if I can say, the modern day Princess Diana.”

READ MORE: King Charles and Queen Camilla searching for jobseeker with eye for 'complex' issues

READ MORE: Prince Harry's secret royal move speak volumes after 'peace talks' with top aides

In his new book The Royal Butler: My Remarkable Life of Royal Service , Grant - who worked with the royals between 2004 and 2011 - mainly as a butler for King Charles, but occasionally seconded to work for Queen Elizabeth - first met Kate during the early years of her romance with Prince William.

Comparing her humour to that of Princess Di, he continues: “Diana used to do things at Sandringham to make the staff laugh by poking her head out the window and pulling faces, and Kate was doing the same kind of thing. She is everything you can imagine, she is a beautiful and intelligent woman.”

Grant, a Scot, had wanted to work for the royal family ever since a childhood dream, in which he was dancing with Queen Elizabeth and spent most of his time with them in Highgrove, the stunning Gloucestershire palace that King Charles shared with William and Harry.

Contrasting his reception from Kate and William, who he says "took a while" to trust him, he recalls how Prince Harry greeted him for the first time with a water balloon fight.

Recalling how tight knit the princes were back then, he says: “William and Harry were so close, as brothers go. With many siblings, you can be close as children and then maybe drift a bit as you grow up in your late teens and early 20s, but William and Harry were the opposite.

“I don’t know if it's because of their mother’s death, but they were inseparable. They were hanging out together, going to pubs together, just having fun together.

“If I had been told all those years ago that they were going to fall out, I would’ve bet £100 that it would never happen. Even when the rumours (of a rift) first started, I was saying publicly to the press that they would never fall out, that’s how sure I was.

“And when all the conflict really started, I was asking myself ‘Why has this all gone so badly wrong?’ I couldn‘t wrap my head around it. Now they’re not even speaking to each other, and they used to speak all the time. It’s really sad.”

Grant also believes that any reconciliation between the princes may happen away from the spotlight. He says: “I think families fall out and families can heal, but it’s never the same. So yes I can see a reconciliation, I can see Harry coming back, but not in the Firm as it used to be.

“I don’t see Harry and Meghan ever on the Palace balcony for Trooping the Colour for example, but I can see the family patching things up behind closed doors and working towards the King seeing his grandchildren [Archie and Lilibet]. I think that's what they're trying to work towards. I think they could be thinking ‘Let's just be a family behind closed doors and move on from this rift from our point of view, not from the public’s point of view’.”

Despite hoping for a reunion between the Sussexes and the wider Windsor family, Grant went on to say that “things are such a mess right now”, and admitted: “I think we have to accept that there is a real possibility that we may never see them as a united family in public.”

But he reveals King Charles to be an exceptionally compassionate man and believes he may be the orchestrator of any reconciliation in the future, saying: “The thing that surprised me was how genuine and nice he was.”

He recalls how he would be in the middle of serving dinner, saying: “I would hear ‘Oh and how are you today?’ and I’d ignored him (King Charles) because I thought he was talking to the guests.

“Then he’d say my name and ask me again, and then he’d start saying ‘How’s your mum? How’s your papa? How’s your brother? How’s your home?’

“If I was having something done, he’d always know and remember what was going on. He’d say ‘Did that thing get done in your house?’ His kindness and compassion would catch me off guard every single time.”

Certain that Harry will have kept up some kind of communication with his father, in light of his illness, Grant continues: “Charles is a very compassionate man. So, even if William - as the big brother - is angry at what Harry has done and maybe has more reservations about meeting up with Harry, I think the King, at this point in his life, will be thinking ‘Let’s look at the bigger picture. Life’s too short, and family is all you’ve got’.”

He also believes Harry will want to heal the rift with the king. He says: “I think Harry does want to reunite with his father, because at the end of the day, Harry is aware that his father has not been a very well man, because they were very close and that doesn’t always change.”

Clearly a big fan of the King, Grant recalls a touching moment when he introduced him to the late Queen at a banquet at Kew palace.

Laughing, he says: “I’ll never forget, I was so focused on the job, and so overwhelmed and excited to be on her service and I was thinking, ‘Don’t do anything wrong, Grant. Don’t put down the wrong plate, don't drop the sauce, don't overfill the glass,’ all these things.

“I remember going over to offer the Queen the vegetables and suddenly Charles looks around at the Queen and over to me and says ‘Oh Mummy this is Grant, my newest butler’. And I'm thinking ‘Oh god not now, not over the vegetables!’”

In light of the news that William and Kate, along with their three children George, Charlotte and Louis, are set to relocate to Forest Lodge on the Windsor estate, from their current home Adelaide Cottage, Grant shares his thoughts on the fate of Buckingham Palace.

“When it comes to William, he is used to smaller houses like Highgrove, because he didn’t grow up in the huge palaces or castles,” says Grant. “So I think there’ll be a transition where Windsor becomes the hub of the monarchy.

“As Forest Lodge is on the Windsor estate, that whole area will become the royal HQ. And then Buckingham Palace could just be open year round as a tourist hotspot, while also operating as the royal office, because it is such a landmark of the royal institution.

“So, I think Windsor will become the embodiment of the Firm as William and Kate move into their forever home. Living in Forest Lodge will be a lot cheaper than living in Buckingham Palace. Also, William has long championed homelessness causes, and it's a bit hard to support the homeless when you’re living in your massive castle, so I think he’s aware of that.

Grant Harrold’s book The Royal Butler: My Remarkable Life of Royal Service is available from August 28th.