This is the sweet promise that William made Kate before they got married

Prince William and Kate Middleton tied the knot in April 2011, saying 'I do' in front of millions of people across the globe. The couple started dating while studying at St Andrew's University, and during the early days of their relationship William set up a support hotline for Kate to help her deal with the pressures of royal life.

However, the couple split briefly in 2007 with William later addressing the break-up during their engagement video, saying: 'We were both very young. It was at university, we were sort of both finding ourselves as such and being different characters and stuff, it was very much trying to find our own way and we were growing up.’

He continued: ‘It was just sort of a bit of space and a bit of things like that, and it worked out for the better.’

According to one royal expert, they rekindled their relationship during a make-or-break trip.

In Andrew Morton's 2011 biography, William and Catherine, he wrote: 'Kate and William, under the assumed names of Martin and Rose Middleton, bid farewell to the paradise island of Desroches in the Outer Seychelles where they had spent a sublime week renewing their love affair.'

Author Marcia Moody has also written about their getaway, saying: 'They stayed in the Desroches Island Resort, checking in under the names Martin and Rosemary Middleton, and went kayaking and snorkelling in the shallow coral reef.'

And according to the experts, William made a very special promise to Kate on this trip. The now-Duchess of Cambridge had to pull out of a charity race due to the pressures of palace protocol, but William told his future wife that they would spend the next few years really making the most of life before they walked down the aisle and settled into serious royal-life mode.

'For the next few years, they would work and enjoy their lives, knowing that at some point when the time was right, they would be husband and wife.'

And the rest is history.