The royal family didn't expect Kate Middleton and Prince William's love story to last.

It was in 2001 that they first crossed paths at the University of St. Andrews.

Most people believed it to be a short-lived trend.

William did a lot of different jobs to learn about Britain.

After finishing college, Kate struck out on her own.

They've been married for over a decade and have three children.

They've spent most of the last 20 years together.

Their love tale was discussed by royal author Andrew Morton.

It was always destined for the Duke and Duchess of Cambridge to be together.