One Direction was a popular boy band formed on The X Factor consisting of 5 members - Harry Styles, Niall Horan, Liam Payne, Louis Tomlinson, and Zayn Malik. Harry Styles was the youngest band member while Louis Tomlinson was the oldest. Some of their most popular early songs included What Makes You Beautiful and One Thing. Most of their fans know them from their time on The X Factor and songs like Up All Night and Midnight Memories. Their first film was called This Is Us.