Prince William and Catherine, Duchess of Cambridge with Prince George and Prince Louis explore the Adam White and Andree Davies co-designed garden ahead of the RHS Chelsea Flower Show. Picture: Reuters

Theirs is a fairy-tale romance. In 2001 while students in residence at St Salvator's Hall at the University of St Andrews, a striking Kate Middleton reportedly caught Prince William's eye at a charity fashion event.

But now, according to royal author Andrew Morton, things could have worked out differently for the royal couple. In his 2011 book William and Catherine, Morton had claimed that William was "falling in love" with the niece of Camilla Parker Bowles before meeting Middleton.

The Duke of Cambridge was 17 at the time when Emma Parker Bowles appeared on his radar. A palace insider said William would “gaze adoringly” at Emma, who was 25 at the time, The Express reported.

A source told the Sunday People in 1999: “He was looking lovingly at Emma and she was hanging on his every word.

“Sometimes he gazes at her so adoringly that it becomes a bit embarrassing. He looks every inch a young man who is falling in love.”

When Kate and William married in 2011, Parker Bowles was invited to their nuptials. “I was surprised because I know he didn’t invite a lot of people," she told E!