The Queen Consort has recorded a personal tribute to the late Queen, recalling her "wonderful blue eyes" and saying: "I will always remember her smile."
In the interview, which will be shown in full this evening, Camilla speaks of how Queen Elizabeth II carved out her own role for many years in the "difficult position" of being a "solitary woman" in a male-dominated world.
"I can't remember anyone except the Queen being there," the Queen Consort adds, being among the majority of the nation for whom, until now, the Queen was the only British monarch they had ever known or could recall.
The tribute will be aired on the BBC shortly before the national minute's silence at 8pm.
Camilla adds: "She's been part of our lives forever. I'm 75 now, and I can't remember anyone except the Queen being there.
"It must have been so difficult for her, being a solitary woman.
"There weren't women prime ministers or presidents. She was the only one, so I think she carved her own role."
Remembering the late monarch, Camilla also says: "She's got those wonderful blue eyes, that when she smiles they light up her whole face.
"I will always remember her smile. That smile is unforgettable."
On the eve of her Platinum Jubilee in February 2022, Queen Elizabeth endorsed the then Duchess of Cornwall as "Queen Consort" when the time came, saying it was her "sincere wish".
She called on the public to back both her daughter-in-law and Charles when he became King.
It was a shrewd move from the monarch, in her twilight years, setting her affairs in order and ensuring as smooth a transition as possible.
It ended years of debate over what Camilla - Charles's former mistress - would eventually be called.
Camilla was blamed for the breakdown of the prince's marriage to Diana, Princess of Wales, and, when news of their affair first came to light, she faced vitriolic criticism.
But in the decades after the Waleses's divorce, the untimely death of Diana in 1997 and Camilla's acceptance into The Firm, the public mood towards the former Mrs Parker Bowles has softened.
Following her wedding to Charles in 2005, Camilla very gradually took on a more prominent position within the Royal Family, including riding next to the Queen in her Diamond Jubilee carriage procession in 2012.
She also began to attend the state opening of parliament and was made a privy counsellor in 2016 ahead of the Queen's official 90th birthday.
The Privy Council is a formal body of advisers to the UK Sovereign.
When addressed in full, she is now referred to as Her Majesty, Queen Consort Camilla, and is expected to be crowned Queen at the King's coronation.