By the 1970s, John Wayne was coming towards the end of his career as a Hollywood star.

In 1973, aged 65-years-old, he had been living with one lung for the best part of 10 years and was suffering from emphysema on the remaining one.

That year, he released two Westerns, which aren’t remembered as his best but saw the ageing icon carry on with much determination.

One of these films was The Train Robbers, which co-starred Ann-Margret as a feisty widow who works alongside three cowboys recovering a cage of gold.

Despite his health problems on the movie, Wayne refused to delay filming and strived forward. Ann-Margret had fond memories of her co-star’s tenacity during this period.

Ann-Margret recalled: “Duke was still a strong, rugged, formidable man, larger-than-life and incredibly personal. He was a big teddy bear, and we got along famously. Duke gave me the confidence I lacked.” The Viva Las Vegas star appreciated this, given that 1972 had been a very difficult time in her life, having been seriously injured when performing in her Lake Tahoe show. Regarding the confidence boost she needed, the actress had to overcome her fear of horses as there was much riding for her character.

It was here that Wayne gave her support and helped her overcome this obstacle. Yet even before shooting started, Duke had fractured two of his ribs, which was so painful he struggled to sleep at night. As a result, Duke’s action scenes in The Train Robbers had to be scaled down, with co-star Rod Taylor remembered Duke being “slightly” infirm during the shoot. The Time Machine star said the Western legend had trouble balancing and understandably needed afternoon naps.