The original plan was that there are only two episodes. So, they made Godfather I and Godfather II in only 4 years. However, the director, Francis Coppola, felt that Michael Corleone was somewhat sinful, especially at the end of Godfather II, Michael gave order to kill his brother, and he wanted to show that he would feel remorse in the rest of his life. So, he decided to make episode 3. The director made Michael to feel unbearable pain of losing his beloved daughter and at the died alone. The tone of Godfather III is heavy. In my opinion, Godfather movie should stop after Godfather II. Actually, Godfather III was not a hot box movie like I and II when it was released around late 1980.
