Harry Styles first hit our screens in 2010 on the UK’s X Factor when Simon Cowell plucked the 16-year-old and four fellow hopefuls ( Zayn Malik, 28, Niall Horan, 27, Louis Tomlinson, 29, and Liam Payne, 27) on to a stage together. And while an artificially-created boyband seems like a recipe for arguments, power-trips and just all round incompatibility, One Direction quickly became the biggest boy band on the planet. Nice work, Si.