Machibet CasinoKate Middleton and Prince William ‘made a secret pact’ after several breakups, royal biographer claims | The Sun - Machibet777 APP

IT'S hard to believe that 10 years ago this week Prince William announced his engagement to long-term girlfriend Kate Middleton.

Fast forward a decade and the Duke and Duchess of Cambridge are proud parents to George, Charlotte and Louis.

But according to royal expert Katie Nicholl, the royal couple's relationship wasn't always smooth sailing.

In her book Kate: The Future Queen, the royal correspondent claims the couple broke up and reconciled several times.

In 2007, the expert claims Prince William felt under pressure to propose in 2007 which led to him reportedly calling time on their relationship during an hour-long phone call.

However, the break-up reportedly only lasted a couple of months and the expert claims Kate and William made a "marriage pact" while on holiday.

She wrote: ";There on the paradise island, William promised Kate that he was in the relationship for the long term.

“For the very first time, they talked seriously about marriage, and with the ocean before them and beneath the night sky, they made a pact to marry."

As part of their agreement, William agreed he would only pop the question when he'd finished his army training.

Discussing their short split during their engagement interview in 2010, Kate said it was difficult not to be "consumed" by the relationship at first.

Giving insight into how she dealt with the split, she added: "At the time, I wasn't very happy about it but actually it made me a stronger person.

"You find out things about yourself that maybe you hadn't realised, or I think you can get quite consumed by a relationship when you are younger.

"I really valued that time for me as well although I didn't think it at the time. Looking back on it."

Kate Middleton and Prince William ‘made a secret pact’ after several breakups, royal biographer claims