How did Louis Walsh become famous?

He managed the bands Boyzone and Westlife. He also managed the lead singer of Boyzone, Ronan Keating when he went solo. He then became a judge on Popstars: The Rivals where he mentored Girls Aloud and then became a judge on the UK X Factor. He joined the show when it first started and is the only orginal judge still on the panel. He mentored series 1 runner up, G4 and series 2 winner, Shayne Ward and series 5 runner up, JLS.