Few of us royal fans need reminding that the romance between Prince William and Princess Kate started when they were studying at St Andrews University in Scotland, but it would seem that the royal couple's paths crossed ten years before that. Vanity Fair's royal correspondent and best-selling author, Katie Nicholl, claims Prince William may have first caught Kate's eye when their schools' hockey teams played each other.

When William - who is celebrating his 43rd birthday on Saturday - was a pupil at Ludgrove Prep School his sports team mates played Kate's school, St. Andrew's Prep, for a hockey match. In her book, Kate: The Future Queen, Ms Nicholl writes: "Although she wasn't especially interested in boys, the arrival of one particular young man had caught her attention."

She continues: "Nearby Ludgrove Prep school would often play matches against St. Andrew's Prep, and there was much excitement when Prince William, a left back on Ludgrove's Colts team, came to St. Andrew's to play a hockey match when he was nine years old.

"William, like Kate, loved sports and was one of the best hockey and rugby players in his year. Of course, the arrival of the prince generated a flurry of excitement."

Despite the pair meeting officially when they were both enrolled at St Andrew's University in 2001, it also came to light that Kate had chosen the same expedition company as her husband, Raleigh International, for her gap year.

The pair spent ten weeks trekking, helping locals and building in Chile, albeit a few weeks apart. Malcolm Sutherland, who ran both expeditions, has called the coincidence "absolutely crazy."

Mr Sutherland said: "For me, it was a normal assumption that everybody else would have realised what that connection was. I think a lot of people don't realise there is that common connection there in their pasts."

William and Kate at St Andrew's University, initially studied in the same Art History course, but William later switched to Geography. They became close friends, and their relationship reportedly "blossomed" during their second year when they lived together in a student house.

It soon became public knowledge that William and Kate were more than friends when she joined him on a family skiing trip in Klosters.

The pair eventually married at Westminster Abbey on April 29, 2011, and millions of royal fans across the world got to witness the latest royal wedding from the comfort of their own homes, as the wedding was broadcast on television.