The Krays were identical twin brothers, Ronnie and Reggie Kray, who became notorious gangsters in London during the 1950s and 1960s. They led a criminal organization involved in various illegal activities, including extortion, robbery, and murder. The Krays were known for their violent behavior and connections to the East End of London. Their criminal empire attracted significant media attention, and they were often seen as anti-heroes by some in the public. The twins were eventually arrested in 1968 and sentenced to life in prison for their crimes. Their story has been depicted in various films and books, highlighting their impact on British crime culture.