King Charles is a doting grandfather to the Wales kids - but has barely spent any time with Prince Archie and Princess Lilibet.
Prince Harry and Meghan Markle's children, who are sixth and seventh in line to the throne, spend most of their time in California away from the Royal Family.
It's not been announced whether the Duke and Duchess of Sussex will attend King Charles' Coronation, but it's believed their children definitely won't be going.
Despite being the grandchildren of the new King, it is believed that Prince Archie and Princess Lilibet have not been invited, with sources citing that they are "very young".
However, it's been claimed in a new book that Archie and Lilibet are "always in Charles' heart" and he has struggled with not having a relationship with his grandchildren.
In Robert Jobson's new book, 'Our King', the royal correspondent reveals behind-the-scenes details about the Royal Family, including Charles' anguish over the Sussex kids.
Jobson writes: "Unfortunately, due to the poor relationship with his second son Prince Harry and his wife Meghan, Charles has spent hardly any quality time with his other grandchildren, Archie and his sister, Lilibet Diana Mountbatten-Windsor.
"But those close to him say they are always in his heart. It is one of the reasons he finds the estrangement from his second son so difficult to cope with."
Charles went to visit Archie for the first time shortly after he was born, but Jobson says Harry and Meghan were already plotting to leave the country.
He adds: "A week after Archie was born in May 2019, Charles had gone to see Harry and Meghan at Frogmore Cottage, and was thrilled as he cradled the baby boy in his arms.
"But even then, the Sussexes were planning their escape from the Firm."
Lilibet was born in California in June 2021 and Charles finally got to meet his granddaughter in the flesh a year later.
Both Charles and his wife Camilla, the Duchess of Cornwall, were said to be "absolutely thrilled" to see Harry and Meghan and their children when they travelled briefly from California for the Queen's Jubilee last year.
"It was fantastic to see them. It was wonderful to have them back in Britain," a senior source said.
"The prince [Charles] and the duchess were absolutely thrilled to see them.
"The prince [Charles], of course, hasn’t seen his grandson Archie for a bit of time and so it was very, very, very special to have some time with him.
"He hadn’t met Lili, his granddaughter, and so to meet her was very emotional, a very, very wonderful thing."
Archie and Lilibet automatically became a prince and princess upon their grandfather's accession due to rules set out by King George V in 1917.
But their titles were only officially confirmed earlier this year when Lilibet's christening was announced.
It is understood Lili's title of princess and Archie's title as a prince will be used in formal settings, but not in everyday conversational use by the couple.
A spokesman for the couple said: "The children's titles have been a birthright since their grandfather became Monarch. This matter has been settled for some time in alignment with Buckingham Palace."
The royal family’s official website has been updated to these new titles, as they were previously Master Archie Mountbatten-Windsor and Miss Lilibet Mountbatten-Windsor.
However, a source claimed that Harry and Meghan were "frustrated" that Buckingham Palace failed to immediately recognise their children as prince and princess.
They said: "It's no secret among their friends Harry and Megan were frustrated Buckingham Palace failed to immediately recognise Archie and Lilibet’s elevated status on its website.
"It was compounded further when the Prince and Princess of Wales’s titles, and those of their children, were swiftly changed following the Queen’s death in September."
OUR KING Charles III: the Man and the Monarch by Robert Jobson goes on sale on April 13.
