While the line of succession will remain unchanged, the number of royals carrying out public duties is likely to be pared back during Charles’ reign, according to royal historian Hugo Vickers.
The writer and royal biographer has profiled several 20th century figures, including the Queen Mother and Princess Andrew of Greece.
Speaking to Express.co.uk, he said: “I think Prince Charles’ wish to slim down the monarchy, which I understand where he’s coming from, but I think he may find it quite difficult actually.
“You do need people to do these jobs that cannot be done by the monarch.
“So, if Prince Charles isn’t careful, he’ll end up with just him, Camilla, Prince William and Kate, and I suppose the little ones growing up.”
The royal expert also touched on Prince Harry and his wife Meghan Markle’s dramatic exit from the Royal Family last year.
Harry and Meghan moved to North America and have since settled in Montecito, California, where they are raising their two children, Archie Harrison and Lilibet Diana.
Mr Vickers said: “Of course, Prince Harry is out of the scene and the Princess Royal, Princess Anne, she’ll go on doing things.
“Prince Edward will go on doing things and of course the members of the Royal Family, who are actually extremely supportive, they will gradually fade into the background.
“They are sort of the equivalent of life peers, people like the Gloucesters and the Kents and Princess Alexandra.
“They are all of a certain age now and they’re not going to be doing quite so much.”
Mr Vickers suggested that in the next royal era there could also be expanded roles for the Queen’s granddaughters, princesses Beatrice and Eugenie.
However, he also referenced the potential pitfalls the sisters may encounter due to their father Prince Andrew’s alleged links to the sex offender Jeffrey Epstein.
Mr Vickers said he “felt sorry” for Beatrice and Eugenie, describing them as “very sweet girls” who could “contribute a lot”, but have “the problem of the father”.
He added: “But I wonder whether they couldn’t use those to princesses a bit more, a bit better.
“They do do a certain amount, they have jobs, but they also do charitable work, so they have found a sort of balance in a way.”
According to another royal expert, Charles may have inherited his wish for a slimmed-down monarchy from his father, Prince Philip.
Gyles Brandreth, who was a companion of the late Duke, recounted earlier this year how Philip had spoken about the Royal Family’s extraordinary growth since he married into the institution.
Speaking to Express.co.uk in May, the journalist and broadcaster explained that he thought Princess Anne and Prince Edward would take up central royal roles alongside Charles and Camilla once the Queen passes away.
Prince William and Kate were also marked out as the “next generation” of royalty by Mr Brandreth.
He said: “It will be a leaner machine going forward and I think the Duke would have quite of liked that.”
Source: EXPRESS CO UK