One Direction 5 years Anniversary

Harry Styles pens note to fans on One Direction's Anniversary

The hunky singer took to Twitter today to celebrate one very special milestone—#5YearsofOneDirection. Yep, believe it or not, it's been five years since Simon Cowell grouped Harry, Louis TomlinsonNiall Horan, Liam Payne and Zayn Maliktogether to create the ultimate boy band of our time.