Maranzalla was the leader of a criminal ring specializing in extortion, gambling and armed robbery. It was also rumoured that he was padrone to Fanucci, a known extortionist who relied on his connection with Maranzalla to remain 'untouchable'.
However, when Fanucci was killed by Vito Corleone, there was no response from Maranzalla, and it was assumed that the two were not connected.
Maranzalla is possibly based on Giuseppe Morello, who was a Mafia leader in New York City in the early part of the twentieth century. He was also padrone to Ignazio Lupo, on whom Fanucci is based. His name of course is similar to that of historical capo di tutti capi Salvatore Maranzano.