They were and remain two of the greatest icons of Hollywood westerns. Although Eastwood was primarily working in television on the western Rawhide from 1959 to 1966 while Wayne was riding across the big screen, there was a golden opportunity for the pair to work together in 1973. By then, the younger star was an acclaimed movie star, thaks to the likes of The Good, The Bad and The Ugly, which is back on our TV screens tonight. He had also started branching out into directing, but Wayne was not at all happy with his efforts and was very vocal about it.

Eastwood had struck gold by teaming up with Sergio Leone for his Dollars Trilogy. The third and final movie – The Good, The Bad and The Ugly, came out in 1966 and was an instant commercial smash.

Five years later, Eastwood directed his first film, Play Misty For Me, and also launched the Dirty Harry saga. He was hot Hollywood property and in 1973 directed his first western, High Plains Drifter.

Wayne had actually been offered Dirty Harry first. He turned it down, something he later regretted, admitting, “I made a mistake with that one.”

In 1973 Eastwood sent Wayne the script for a new project, The Hostiles, that he thought would be perfect for the two of them.

Eastwood continued: “High Plains Drifter was meant to be a fable: it wasn’t meant to show the hours of pioneering drudgery. It wasn’t supposed to be anything about settling the West.”

Wayne was also infamously conservative and opposed to anything without a clear moral (in his view) code. He refused to shoot enemies in the back on screen or do anything to dishonour what he saw as the heroic past of his beloved nation. The veteran star blasted the ending of High Noon as “the most un-American thing I’ve ever seen in my whole life.”

Wayne also famously turned down an offer from Steven Spielberg, blasting the film as ‘Un-American drivel.”

Eastwood, in contrast, was attracted to stories and characters with shaded, ambiguous morality. Even so, he sent the script for The Hostiles to Wayne one last time.

Wayne’s son Mike handed it to him while they were out sailing. The star simply grunted “This piece of sh** again” and threw it overboard into the ocean.

The John Wayne biography – Duke, a Love Story –  recounts how he bluntly dismissed The Hostiles: “This kind of stuff is all they know how to write these days … someone like me and Eastwood ride into town, know everything, act the big guys, and everyone else is a bunch of idiots.” 

In the end, the film was never made, but the two stars finally met in person for the first time in 1976 when Wayne was making The Shootist. When he heard Eastwood was visiting the set, he only cared about one thing, and it had nothing to do with previous exchanges.

Co-star Ron Howard recalled that all the veteran wanted to know about was Eastwood’s politics. Reassured that he was also a staunch conservative, The Duke was happy to be introduced.

THE GOOD, THE BAD AND THE UGLY IS ON ITV4 TONIGHT AT 9.15PM