In The New Royals, author and journalist Katie Nicholl said an unnamed family friend revealed the Duke of Sussex met with his father earlier this year to help rebuild their relationship.
However, it is said the meeting did nothing to solve their rift, with Harry and Meghan reportedly not only late to the meeting, but suggested they use a family mediator.
In an extract published in Vanity Fair, Ms Nicholl described the meeting as ‘more awkward than cordial tea with the Queen’.
Camilla allegedly told Harry the idea of a mediator was ‘ridiculous’ and they would work together as a family to resolve their differences.
The family friend said: ‘Harry actually suggested that they use a mediator to try and sort things out, which had Charles somewhat bemused and Camilla spluttering into her tea.’
The book also claimed Prince William and Kate were ‘relieved’ after finding out Harry and Meghan would be moving to the US.
Ms Nicholl claimed the Prince and Princess of Wales, then Duke and Duchess of Cambridge, felt the ‘drama was gone’ after the Sussexes announced their departure.
However, the Queen reportedly felt ‘hurt and exhausted’ by the move and was ‘disappointed’ when the couple didn’t return to the UK with Archie and Lilibet for her annual ‘sleepover’ in Sandringham with the grandchildren and great-grandchildren.
The source told Nicholl: ‘The Queen was very hurt and told me, “I don’t know, I don’t care, and I don’t want to think about it anymore.”‘
King Charles now wants to heal the divide between Harry and the rest of the family, according to the book.
In his first televised address to the nation, the new King made clear he was extending an olive branch to the Sussexes.
He said: ‘I want also to express my love for Harry and Meghan as they continue to build their lives overseas.’
The couple were coincidentally visiting the UK when the Queen passed away, meaning they were present during the national period of mourning.
Harry put on a united front with William as they greeted well wishers outside Windsor Castle with their wives.