Like 25-year-old Kate, Katherine Worsley is from far more humble stock than the royal dynasty into which her life is interminably linked.

A member of a high-Anglican family with few connections to the monarchy, Katherine came not from the home counties or metropolitan London but Yorkshire.

In November 1956, just three weeks after his 21st birthday, the Duke of Kent joined other members of his regiment for lunch with Sir William Worsley and his family at their home, Hovingham Hall.

Here, the royal guest was seated next to the host's beautiful, blonde 23-year-old daughter, Katherine. The Duke was immediately smitten and, before long, was regularly calling in at Hovingham to meet up with the woman with whom he'd fallen head over heels in love.

It appeared an unlikely union. Friends noted that Katherine was more mature than the Prince. Despite her age, she was ready to settle down. He, meanwhile, continued to enjoy a reputation for enjoying the high life, one which was far removed from the more sedate public world of the Windsors.

Like William today, Prince Edward was also said to have a roving eye.

Whereas the Duke of Kent was extrovert and the life and soul of any party, Katherine Worsley was shy, at her happiest within the bosom of her united and stable family. No scandal whatsoever was attached to the Worsley name.

Despite being invited to the Kent family home of Coppins, where she appeared to make a good impression on the Duke's family, Katherine was to face what appeared an increasingly insurmountable problem: the disquiet of the Prince's oh-so-royal mother, Princess Marina.