The move marks the latest setback for the king’s brother as the scandal over his ties to the convicted American sex offender Jeffrey Epstein continues to cast a long shadow.

King Charles was thrown into panic over the future of the British monarchy when he learned Prince William and Kate Middleton were expecting their first child, fearing the stability of the royal line could be shaken if their baby was a girl.

Charles's biographer, Jonathan Dimbleby, wrote in The Prince of Wales: A Biography that Diana "unexpectedly announced that she was not prepared to go" to South Korea. It was only when Queen Elizabeth got involved that Diana agreed to take part in the tour.