Based on the success of The Godfather (1972) and The Godfather Part II (1974), the third installment, The Godfather Part III, released 16 years later in 1990, was only done because director/co-writer Francis Ford Coppola's film One From the Heart (1982) was a monumental financial failure. However, he did make eight other films before doing The Godfather Part III.
Don't get me wrong, Part III was a well-made movie, nominated for a Best Picture Oscar, but the Corleone saga ended with Part II--even Francis Ford Coppola said this. It seemed like the third film was made up drama attempting to create new Corleone family turmoil. Every time they mentioned some aspect from the first two films, even when they showed photos of the previous characters, namely Don Vito Corleone and his two other sons Sonny and Fredo, it made the third film seemed so forced. I knew right from the start, its main purpose was to show the death of Michael Corleone, which it did, with very little fanfare.
It was an unnecessary film which soiled the Corleone saga. Part II ended masterfully, with Michael having his older brother Fredo killed for betraying the family, then having to live with this for the rest of his life. As it stands, we now get to remember the family saga ending with the death of his daughter Mary, who no one liked at all, and Michael's uninspired slumped over death.