Earlier this month, the Queen celebrated the 70th anniversary of her reign - becoming the first British monarch to do so - and used the special moment to announce that she would like Camilla, Duchess of Cornwall, to be known as Queen Consort when Prince Charles becomes King.
Until now, Camilla's future role had been unclear, with suggestions that she may be referred to as Princess Consort when her husband eventually takes the throne.
In a message shared with the public, the Queen wrote: 'I would like to express my thanks to you all for your support. I remain eternally grateful for, and humbled by, the loyalty and affection that you continue to give me.
'And when, in the fullness of time, my son Charles becomes King, I know you will give him and his wife Camilla the same support that you have given me; and it is my sincere wish that, when that time comes, Camilla will be known as Queen Consort as she continues her own loyal service.'
A spokesperson for Clarence House said that Prince Charles and Camilla were 'touched and honoured' by the announcement.
However, royal author Christopher Andersen claims that Prince William and Prince Harry were 'completely blindsided' by the news and that it is 'driving a wedge' in the family.
The author of Brothers and Wives: Inside the Private Lives of William, Kate, Harry and Meghan, told Us Weekly: 'It’s just whether or not they can get over this bad feeling. Then, of course, [the] Queen’s health and these other considerations are there. I don’t think it helped with the Queen announcing that Duchess Camilla will be Queen Consort, and that’s another issue.'
He continued: 'I can tell you right now that the boys were completely blindsided by this.'
Andersen also claims that the Queen was 'miserable' during Charles and Camilla's wedding ceremony, and that she was 'begrudgingly letting him do this and one of the key elements was he promised Camilla would never be called Queen Consort.'
However, the monarch's mind was reportedly changed as a result of Camilla's 'dedication and loyalty to The Firm', as 'she has more than proved to her that she has what it takes.'
The Palace has not commented on these claims.
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Jadie Troy-Pryde is News Editor, covering celebrity and entertainment, royal, lifestyle and viral news. Before joining the team in 2018 as the Lifestyle and Social Media Editor, she worked at a number of women’s fashion and lifestyle titles including Grazia, Women’s Health and Stylist, and now heads the Marie Claire UK news desk.