Loving is the true story of Richard and Mildred Loving, whose landmark 1967 Supreme Court case abolished laws that prohibited interracial marriage. The film reteams Edgerton with Midnight Special director Jeff Nichols, focussing on the couple rather than the court case.

Joel Edgerton and Ruth Negga in Loving

As he approached making the film, the name of the case haunted Edgerton. "I kept seeing the words Loving v Virginia," he says. "I saw those words together and I thought it was very powerful obviously. It felt like humanity versus the system, which is really what the movie is about. I just kept thinking about a human quality, a human desire that we all share versus the system that's all about everything else."

He particularly enjoyed Nichols' low-key approach. "Jeff had the opportunity, in taking that real-life story, to really dial it up, to make it Hollywood," Edgerton says. "He refused to do that, and in that sense the fabric of the movie is very real. For example, when the Supreme Court handed down the decision, Richard and Mildred weren't in the courtroom. And you imagine the Hollywood version of that: they punch the air and everyone's hugging each other. But the reality was that Richard was mowing the lawn when that phone call came through."

Edgerton was also challenged by playing a man of so few words. "I thought having less to say would make the accent easier," he jokes. "Ironically, it made it more difficult. With a character like John Connolly [in Black Mass], you really get to fly on the rhythm of an accent. And rhythm is so much a part of what an accent is. With this role, I don't think I've ever had to think so specifically about silence."

This required a lot of work to develop meaning to each moment of shy awkwardness, turning them into words that Richard was unable to express. "Just because you're not speaking doesn't mean you're not communicating," Edgerton says. "When you watch Richard, the cogs are turning, but the mouth isn't opening."

To increase the authenticity, the film was shot in the actual locations where the events took place. "We shot at the jail and at the courthouse, and they all had their own ghosts that swam around inside the movie," Edgerton says. "But going to the grave site where Richard and Mildred were buried suddenly took the importance to a whole other level for me."

Watch the trailer and clip for Loving: