Bernardo Provenzano was an Italian mobster and chief of the Sicilian Mafia clan known as the Corleonesi, a Mafia faction that originated in the town of Corleone, and de facto the boss of bosses. His nickname was Binnu u tratturi because, in the words of one informant, "he mows people down". Another nickname was il ragioniere, due to his apparently subtle and low-key approach to running his crime empire, at least in contrast to some of his more violent predecessors.

The Sicilian Mafia or Cosa Nostra, also referred to as simply Mafia, is a criminal society originating on the island of Sicily and dates back to the mid-19th century. It is an association of gangs which sell their protection and arbitration services under a common brand. The Mafia's core activities are protection racketeering, the arbitration of disputes between criminals, and the organizing and oversight of illegal agreements and transactions.