Fredo was second son to Don Vito Corleone and his wife Carmela though he was an aggressive young man he was also the most sensitive and caring of Vito's sons. When Fredo joined the family business Vito didn't trust him to be effective and relegated him to unimportant tasks. Fredo was also the only family member to support his brother Michael when he announced plans to join the military. When Fredo failed to protect his father from his enemies leading to Vito's hospitalization it added to his feelings of inferiority and was devastated by his father's condition Fredo later moved to Vegas and was taken in by Moe Greene as the Corleones had funded Moe's casino however Moe slapped Fredo when his womanizing got out of hand and even put Fredo in danger by having him dispose of a business partner's body. When Moe refused to sell his casino to Michael Fredo tried to defend him and was warned by Michael about siding against his family. Moe was later killed on Michael's orders. Feeling passed over by his father Fredo supplied financial information about Michael's organization to Johnny Ola which he and Hyman Roth used in an attempt to Kill Michael leaving Fredo outraged. Fredo's betrayal became known to Michael when he let slip that he and Johnny Ola had been to a sex show in Havana when confronted about this Fredo fled in fear for his life Michael later talked with Fredo and discovered he withheld important information about Roth's connection the lawyer Questadt who was on the congressional committee pursuing Michael which led Michael to banish Fredo from the family. Fredo attended Carmela's funeral and was devastated by his mother's death Michael seemingly offered forgiveness to his brother. With Michael's consent Fredo developed a good relationship with his son Anthony and took him fishing however when Anthony was called away Fredo was left alone in the boat with ruthless hit-man Al Neri who shot him in the back of the head, killing him. This had always been Michael's plan and he only spared Fredo for so long to avoid causing upset to their mother. Fredo's murder caused a serious strain in Michael's relationship with Anthony and his wife Kay.