Not stating this as fact just quoting the site that I was led to when searching it. For what it's worth.
Michael Corleone is loosely based on Joseph Bonanno and Vito Genovese.[6] Bonanno became a boss of his own family at a very young age and he relocated some of his businesses to Arizona in the 1960s. Genovese had fled to Sicily in the 1930s due to murder charges and ordered the deaths of rival bosses in the 1950s. Genovese was also infamous for being duplicitous, as well as for his kiss of death, given to Joseph Valachi, just as Michael did with his brother Fredo.
