I’ve written this love story for today’s Daily Express, a forbidden love between the Prince Eddy, the Duke of Clarence, the eldest son of King Edward VII, and Princess Hélène, a Catholic, Prince Philippe, Count of Paris, a pretender to the French throne. They had secretly become engaged, and the lovestruck prince even offered to renounce his throne. But it was not to be.

It took another 125 years for new rules on royal succession to come into force removing discrimination against Roman Catholics, allowing members of the British royal family to marry a Roman Catholic and become king or queen. However, a Roman Catholic royal still cannot become the monarch.