Queen Elizabeth II, in her Platinum Jubilee Address late Saturday, asked that Camilla Parker-Bowles, the second wife of Prince Charles, receive the title of Queen Consort after Charles ascends the throne.
"It is my sincere wish that, when that time comes, Camilla will be known as Queen Consort", the Queen wrote.
A Clarence House spokesman said the "Prince of Wales and Duchess of Cornwall were 'touched and honoured' by the Queen's words", according to the BBC.
It was not expected that the Queen would grant the Duchess of Cornwall this title. Royal rules stipulate that the crown prince's wife automatically becomes Queen when he succeeds to the throne, but given the "uncertainty about public opinion", Camilla was set to instead become "Princess Consort".
References to her as Princess Consort, however, disappeared from the website of Prince Charles in 2018 amid rumours that they "infuriated" him, and he was said to be "insisting" on Camilla having the title of Queen Consort.
In the past, male consorts have usually received other titles, such as the late Philip, Duke of Edinburgh, who died last year, who held the title of Prince Consort, not King. Meanwhile, Camilla is likely "to have a fully-fledged royal role beside Charles".
The Queen's recent endorsement came after she earlier announced that Camilla would become a member of the Order of the Garter - the highest order of chivalry.
On 5 February, the Queen hosted a reception at Sandringham to commemorate the anniversary of her accession to the throne in 1952. The gathering at Sandringham was the largest public event the Queen has attended since a reception at Windsor Castle in October.