True Grit was a godsend for John Wayne, who lobbied for the lead role of one-eyed US Marshal Rooster Cogburn after reading Charles Portis’ novel of the same name.

Duke would go on to finally win the Best Actor Oscar for the part on April 7, 1970, but production was far from easy for him.

Despite being a huge star, he was not in control of casting.

Famously Elvis Presley couldn’t be secured for the supporting role of the Texan La Boeuf, as the singer’s manager Colonel Tom Parker demanded top billing above Wayne himself.

Meanwhile, his True Grit co-star Robert Duvall would end up leaving the Western legend fuming once the shoot had begun.

Duvall was 38 when he played Lucky Ned Pepper in True Grit and had yet to become the Hollywood leading man of his later career. He was known for having a fiery temper just like his old roommate Gene Hackman, who he lived in New York with alongside Dustin Hoffman when they were poor young thespians. All three enjoyed practical jokes, but Duvall and Hackman were known for having short fuses which led to explosive bar fights. Hoffman has previously shared how Duvall ended up incorporating his real-life anger into his performances. The latter would pick out an audience member he pretended to hate and then shouted ‘f*** you!’ when he left the stage following a curtain call.

As a method actor, he became frustrated when Wayne and True Grit director Henry Hathaway’s plans for his character didn’t match up with his. As a result, confrontations on set became commonplace. He said in 2015: “The director and I didn’t get along — I don’t get along with a lot of directors.” And on another occasion, added: “Henry Hathaway… we won’t talk about him.” Duvall became irritated by Hathaway’s dictatorial and aggressive directing style, with the actor remembering: “He’d say, ‘When I say, ‘Action! Tense up, Goddam you.’ It’s hard to work under that as a young actor.” As a result, the pair would have fierce arguments which eventually were interjected by Wayne himself.

True Grit was Duke’s passion project after all and the Western legend ended up fighting with Duvall himself to the point where he threatened to punch him if he didn’t stop arguing with Hathaway. The Lucky Ned Pepper star may never have gotten over his feuding with Hathaway, but would speak highly of Wayne despite this altercation.

Even though he won Best Actor for True Grit, Wayne wasn’t happy with his performance as Rooster Cogburn and later called the award “beginner’s luck”. Yet Duvall admitted: “Wayne wasn’t as bad as some supposedly serious actors I’ve seen who trained at the Actors Studio and all that… Wayne was interesting to be around. He was pleasant and outgoing.”