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 Corleonesi Mafia clan was a faction within the Corleone family of the Sicilian Mafia, formed in the 1970s. Notable leaders included Luciano Leggio, Salvatore Riina, Bernardo Provenzano, and Leoluca Bagarella.