Prince William admitted the death of his beloved "Grannie" The Queen doesn't feel real in an emotional tribute following the Monarch's death at the age of 96.
The new heir to the throne echoed one of the late Queen's most famous quotes in the moving message, saying "grief is the price we pay for love".
He also pledged to support his father, King Charles III, "in every way he can" as he becomes the new Prince of Wales, with Kate taking the title of Princess of Wales.
He said: "On Thursday, the world lost an extraordinary leader, whose commitment to the country, the Realms and the Commonwealth was absolute. So much will be said in the days ahead about the meaning of her historic reign.
"I, however, have lost a grandmother. And while I will grieve her loss, I also feel incredibly grateful. I have had the benefit of The Queen’s wisdom and reassurance into my fifth decade. My wife has had twenty years of her guidance and support. My three children have got to spend holidays with her and create memories that will last their whole lives.
"She was by my side at my happiest moments. And she was by my side during the saddest days of my life. I knew this day would come, but it will be some time before the reality of life without Grannie will truly feel real.
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"I thank her for the kindness she showed my family and me. And I thank her on behalf of my generation for providing an example of service and dignity in public life that was from a different age, but always relevant to us all.
"My grandmother famously said that grief was the price we pay for love. All of the sadness we will feel in the coming weeks will be testament to the love we felt for our extraordinary Queen. I will honour her memory by supporting my father, The King, in every way I can."
William shared a close relationship with his grandmother and the Cambridge family recently moved to Windsor to be closer to the Monarch.
He rushed to Balmoral with his father after doctors became concerned for the Queen's health, however she had already passed away by the time he arrived.
In an interview with Sky News in 2016, he opened up about the Queen's presence in his life as a "strong female influence" after the loss of his mother at a young age.
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He said: "It's been particularly important to me that I've had somebody like the Queen to look up to and who's been there and who has understood some of the more complex issues when you lose a loved one.
"So she's been incredibly supportive and I've really appreciated her guidance."
He also recalled her once giving him an "almighty telling off" at Balmoral. He said: "[ Peter Phillips and I] were chasing Zara around who was on a go-cart, and [we] managed to herd Zara into a lamppost and the lamppost came down and nearly squashed her.
"And I remember my grandmother being the first person out at Balmoral to come running across the lawn in her kilt.
"She came charging over and gave us the most almighty b******ing, and that sort of stuck in my mind from that moment on."
William's tribute comes just hours after William joined his father at a meeting of the Accession Council, during which King Charles was officially declared head of state.
It was the first time he was pictured since Charles used his first speech as King to confirm the Cambridges would be the new Prince and Princess of Wales.
Kate becomes the first person to use the title since Diana, with a source saying she is very aware of the history that goes with it.
They said: The couple are focussed on deepening the trust and respect of the people of Wales over time.
“The Prince and Princess of Wales will approach their roles in the modest and humble way they’ve approached their work previously
“The new Princess of Wales appreciates the history associated with this role but will understandably want to look to the future as she creates her own path.”
This weekend, the Daily Mirror and Sunday Mirror celebrate the life of Her Majesty the Queen with a commemorative special filled with all the key moments from Britain’s longest reigning monarch. Be sure to pick up your copy of the Daily Mirror and Sunday Mirror to get poth pullouts.
