

Initially, this system is highly lucrative for the Kray brothers. Bruno agrees to a fifty-fifty deal with Reg to split London's underground gambling profits in exchange for local protection by the brothers. The brothers are approached by Angelo Bruno of the Philadelphia crime family who, on behalf of Meyer Lansky and the American Mafia, wants to engage them in a crime syndicate deal. On the first night after Reg's release from prison, the brothers have an all-out fist fight, but they manage to partially patch things up. The club is almost forced to close after Ron scares away most of the customers. While Reg is in prison, Ron's mental instability and violent temperament lead to severe financial setbacks at the nightclub. When he is imprisoned for a previous criminal conviction, which he cannot evade, she makes him swear that he will leave his criminal life behind, an oath he never honours due to the allure of crime.

Reg enters into a relationship with Frances, his driver's sister, whom he eventually marries.

One of their first efforts is to muscle-in on the control of a local nightclub, using extortion and brutal violence. The twins unite their efforts to control a large part of London's criminal underworld. Reggie uses threats to obtain the premature release of his brother. At the start of the film, his twin brother Ron is locked up in a psychiatric hospital for paranoid schizophrenia. In the 1960s, Reggie Kray is a former boxer who has become an important part of the criminal underground in London.
