Screenwriter Tom Mankiewicz, who is largely (if unofficially) credited with the final screenplays for both "Superman: The Movie" and "Superman II," died on Saturday, The Hollywood Reporter writes. He was 68.

Mankiewicz was born into a family of Hollywood heavyweights. His father Joseph L. Mankiewicz won two Academy Awards for writing and directing the classic "All About Eve," and his uncle Herman J. Mankiewicz received the Oscar for co-writing "Citizen Kane." Tom's own screenwriting career kicked off in the late 1960s when an unproduced script he wrote led to a string of television variety gigs writing for stars like Nancy Sinatra. After his book for the brief Broadway flop "Georgy" caught the eye of United Artist's, Mankiewicz started a stint as writer of the James Bond franchise scripting the installments "Diamonds Are Forever," "Live And Let Die" and "The Man With The Golden Gun."

After spending the '70s on a number of film projects, the writer was tapped by director Richard Donner to redraft the screenplay for his upcoming "Superman" film. While the original script was written by (and the movie ultimately credited to) Mario Puzo, Donner long proclaimed that it was Mankiewicz who helped him turn the original concept away from camp and towards the heroic tale of Americana that the initial installments of the Superman franchise were best known for. Years later, the writer would get his on screen credit with the release of "Superman II: The Richard Donner Cut" on DVD in 2006.

In his later career, Mankiewicz would himself go behind the camera -directing many episodes of the TV Series "Hart To Hart" as well as the films "Dragnet" and "Delirious."

Mankiewicz passed away at his home in Los Angeles on July 31 after a long battle with cancer.