The man who would be king, eventually: Prince Charles turns 70

Diana

However, the issue that most fascinates the public remains Charles's divorce from Diana, her early death in a 1997 Paris car crash and his subsequent marriage in 2005 to Camilla. Some blame Camilla for the failure of his first marriage.

Opinion polls indicate Charles's standing has never fully recovered from damage suffered during the 1990s. A poll in January 2018 found 9 percent picked Charles as among their favourite royals.

The same poll found 54 percent had favourable opinions of the prince compared to 24 percent unfavourable. His mother and sons William and Harry are viewed favourably by more than 80 percent of Britons.

In a TV interview in 1995, Diana suggested Charles did not want to be king and was not cut out for such a "suffocating" role. Not so, say those who worked with him.

"Charles, the Prince Of Wales, is going to be the best prepared monarch probably in history and I think he'll be a very good king," Lewis said.

Although Charles is loath to talk about becoming monarch, as it will mean the death of his mother, behind the scenes well-prepared plans for the occasion - codenamed Operation London Bridge - are ready.

Until then, his unique life as heir will go on.

"People rightly talk about the privilege and the money and the palaces and the Bentleys," the prince's former aide said. "It is a privilege, but it carries a great burden. I would never wish that life on anyone."

Reuters