According to an author, Meghan Markle planned to capitalise on Diana’s celebrity after marrying Prince Harry, oblivious to the royal line of succession.

In her latest book The Palace Papers, Tina Brown writes: “Star power — wattage — equals leverage in the entertainment world’s ranking system… Unfortunately, she appeared to be unaware of the one important criterion that would determine the fate of her future plans: primogeniture.”

Meghan had no idea that her fame and popularity would never eclipse the Cambridges, who are next in line to the throne. The Duchess of Sussex is far later in the list than Camilla and Kate.

Prince Harry’s royal standing has slipped farther down the line now that Prince William has three children, making him the sixth in line.

Mr Brown notes “when Kate became Queen, Meghan would have to curtsy to her”.

Meghan miscalculated her role in the family back when she married Harry, adds the author. ‘Oblivious’ of her rank, she wanted to step on other royals with her humanitarian gigs.