The interesting comment William made about Kate that completely changed their relationship

Prince William and Kate Middleton met at St Andrews University, starting off as friends before they realised they had a romantic connection. The pair used a number of decoys to keep their relationship out of the papers, and William even set up a support hotline for Kate to help her adjust to life as a royal in the spotlight.

While it is widely known that the pair were housemates before they started dating, over the years many have wondered exactly when things changed for the Duke and Duchess of Cambridge.

In Robert Lacey's book, Battle of Brothers, the historian says: 'Just a month or so into their first term together, they attended a party at which William was getting seriously hit upon by a pushy female student.

'The prince was being polite, but he couldn’t shake her off, and the girl didn’t get the hint — until Kate appeared out of nowhere behind him and put her arms around William.'

He said: 'Oh sorry, but I've got a girlfriend' and he and Kate reportedly 'went off giggling together'.

But the Prince is said to have uttered just three short words during his time at university that would change his relationship with Kate forever.

The now Duchess famously walked the catwalk during her time at St Andrews wearing a sheer dress, and William was floored - reportedly telling his friend, Fergus Boyd: 'Wow! Kate's hot!'

It is believed that after her modelling debut, the royal saw Kate in a different light.

And the rest, as they say, is history!