In 1974, two years after the original Godfather, Francis Ford Coppola released the sequel, starring Al Pacino, Diane Keaton, and Robert DeNiro as young Don Vito Corleone. I am usually not a fan of sequels, as directors typically try to capitalize on the elements that made the success of part I, and typically fail. Well, not here.
First thing to say, it is not possible to watch part II without having seen part I. That would be way too confusing.
We follow two stories in parallel here. We get to the origins of Vito Corleone and his rise to the ultimate Godfather role. Robert DeNiro impersonates younger Vito.
The godfather was born Vito Andolini, in the town of Corleone in Sicily. In 1901 his father was murdered for an insult to the local Mafia chieftain. His older brother Paolo swore revenge and disappeared into the hills, leaving Vito, the only male heir, to stand with his mother at the funeral. He was nine years old.
DeNiro is amazing and totally right for this part. He is a family man at heart, wiling only a better life.
There is a fun reference to the first part, too:
Vito Corleone: I make him an offer he don' refuse. Don' worry.
Most of the movie is dedicated to Michael though. It starts with an assassination attempt and we see him consolidate his power and destroying his enemies ruthlessly, even his own brother, Fredo.
Michael Corleone: I don't feel I have to wipe everybody out, Tom. Just my enemies.
Michael Corleone: There are many things my father taught me here in this room. He taught me: keep your friends close, but your enemies closer.
Michael: I don't want anything to happen to him while my mother's alive.