At the time, Kate reportedly did everything she could to make him stay – playing a waiting game one minute and then hard-to-get the next.
“Just the other week, she said she intended to be photographed at as many places as she could without William to punish him for all those pictures that appeared of him clubbing with other girls," a source told Express.co.uk at the time.
Kate, however, handled things like the Queen she was destined to become.
The future Duchess of Cambridge was photographed around London putting on a brave face, and very much showing Prince William what he was missing.
She was seen out partying, but always kept her cool, and never made a fool of herself.
Eventually, the royal couple managed to patch things up after a few months apart.
Their break seemed to be just what the Prince needed to see what he was missing, and he proposed to Kate in 2010, with the couple marrying in 2011.
When the couple announced their engagement in 2010, they were asked about their 2007 split.
Kate said: “I think 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.
“I think you can get quite consumed by a relationship when you’re younger and, you know, I really valued that for me as well, although I didn’t think it at the time.”
William said of their early relationship: “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.”