Roth secretly plans to assassinate Michael, partly to avenge Moe Greene's murder (as depicted in The Godfather). Roth instructs Ola to befriend Michael's brother Fredo, who provides Ola (and Roth) information about Michael that enables them to make an attempt on his life.
Fredo's decision is most likely a result of resentment toward Michael, by whom he felt he had been passed over. Michael was Fredo's "kid brother," and the fact that their father chose for Michael to take over the "family business" came as a great insult to Fredo, who was neither as intelligent nor as strong.
A rift grows between Pentangeli and Michael, however, that eventually results in Pentangeli betraying the family. Pentangeli's character was created in The Godfather Part II by Coppola and Puzo due to actor Richard Castellano not reprising his role as Clemenza in the sequel.
Following the death of their mother and at Connie's behest, Michael appeared to reconcile with his brother, but secretly ordered Fredo's murder, an act he would regret for the rest of his life and which he eventually confesses to the future pope.
Who attempted to have Michael Corleone assassinated in his home in Lake Tahoe? Hyman Roth gave the order, Fredo Corleone opened the curtains, and Rocco Lampone let the hit men into the compound, either intentionally or by lack of proper security oversight.
How did Michael work out Hyman Roth tried to kill him? The Godfather Explained
Who ordered the hit on Michael Corleone?
Roth, suddenly realizing that Michael is on to him, gives a great speech which, nevertheless, confirms that Roth has long had a secret vendetta against Michael, thereby confirming Roth's guilt… “When Mo Greene was killed… I never asked who gave the order. I said to myself, THIS is the BUSINESS we've chosen!
Fredo later betrays Michael after being approached by Johnny Ola (Dominic Chianese), an associate of rival crime boss Hyman Roth (Lee Strasberg). Ola and Roth tell Fredo that Michael is being particularly difficult in business negotiations between Roth's organization and the Corleone family.
Michael arranges to have Roth killed at the airport where he is about to be taken into U.S. federal custody. Minutes after disembarking the plane, he is fatally shot by Michael's caporegime Rocco Lampone, posing as a reporter. Rocco himself is killed by federal agents as he tries to escape.
Who is the weakest Corleone brother in The Godfather?
In Puzo's novel, Fredo is thought of in the Corleone family as the weakest and least intelligent of the three Corleone brothers, and therefore is given its unimportant businesses to run. Nevertheless, Fredo is the most obedient and dutiful of the Corleone children, despite being largely ignored by his father.
The third and final film in the Godfather saga, The Godfather: Part III, set in 1979, explains that Hagen had died a few years earlier. His son, Andrew, is ordained to the priesthood, and is assigned to the Vatican on Michael's recommendation. While talking with Andrew, Michael remembers Hagen fondly as a great lawyer.
Enraged, Sonny speeds towards Connie's apartment in Hell's Kitchen ahead of his bodyguards. At the Long Beach Causeway toll plaza, Barzini's men trap Sonny and shoot him to death. During a meeting with the other crime family dons to establish peace, Vito realizes that Barzini masterminded Sonny's murder.
As Fredo prays the Hail Mary (which he claimed brought him luck whilst fishing), Neri shoots him in the back of the head, not knowing that Anthony was watching from his bedroom window.
Apollonia had a loving but morganatic(unequal) marriage with Michael in consequence of his desire to own her; they both had a very short marriage. Apollonia was a young teenager and Michael was in his late twenties, as a result, Michael became possessive of Apollonia.
Luca Brasi is Don Vito Corleone's personal enforcer and the only man Vito himself fears. While slow-witted and brutish, Brasi is fiercely loyal with a reputation as a savage and remorseless killer.
Michael wasn't smarter than Tom. He simply thought differently. Tom Hagen was brilliant. That's why he, out of all of Vito's sons, was sent to law school.
Michael did not trust Hyman. Roth hated Michael and what he did to his protege Moe Greene. Michael had an idea who had tried to have him killed in Nevada. He also knew Roth had him brought into the Senate investigation thanks to Frankie later on.
It was unknown if Michael sending Rocco after Roth was to punish him for his previous failure by sending him to his death, or so that he could redeem himself in Mochael's eyes. If I had to guess it was probably both. Regardless, Rocco succeeded in killing Roth, and died loyal to Michael.
Michael removes Hagen as consigliere in favor of having Vito fill the position, restricting Hagen to handling the family's legal business in Nevada, Chicago, and Los Angeles. Michael and Vito explain that the Corleones risk inciting a fight with the planned move to Nevada, and they need a "wartime consigliere".
In the novel, Greene is murdered shortly afterward by Al Neri. At the end of the film, Michael has Greene killed as part of his slaughter of the Corleone family's enemies. Neri surprises Greene while he is getting a massage and shoots him through the eye.
