Based on the book "The Profession of Violence, The Rise and Fall of the Kray Twins" by John Pearson, Legend tells the story of the Kray twins: Reggie Kray and Ronnie Kray. Using violence to get what they want, they start to leave their mark on the London underworld in the 1960s. The movie focuses on the life of Reggie as he seeks to control the psychotic tendencies of Ronald..