The Duke and Duchess of Cambridge met when they were university students so have spent most of their adult lives in love.
But before laying his eyes on his future wife, a young Prince William had a few exciting romances.
As a gorgeous member of the royal family and our future king it's hardly surprisingly that he wasn't short of female fans, but it was one of his pals who stole his heart.
Wills had been pals with Arabella Musgrave since he was a kid but didn't look at her romantically until he was 18, claims royal biographer Katie Nicholl.
Arabella is the daughter of Major Nicholas Musgrave, who managed Cirencester Park Polo Club, and was part of William and Harry's inner circle of trusted friends known as the Glosse Posse.
In her book William and Harry: Behind the Palace Walls, Kate writes: "As she walked through a friend's house party, William did a double-take.
"Arabella had blossomed into a gorgeous-looking girl, and he wondered why he hadn't noticed her properly until now.
"They danced and drank into the early hours, and when Arabella said her goodnights, the prince quietly slipped out of the room to follow her upstairs.
"It was the beginning of a passionate romance and the two spent as much time together that summer as possible."
But in the end he decided to stick to his plan, and ended up meeting and falling in love with Kate Middleton at St Andrews.
William is still pals with Arabella, who now works of head of PR at Gucci.
In 2014 she married George Galliers-Pratt.