Specific rule Christopher Nolan had to agree to when he directed his The Dark Knight films

When creating his trilogy of Dark Knight films, Christopher Nolan was forced to agree to a specific rule in order to get the job.

This now seems inconceivable considering the success Nolan has had since, with two of the trilogy both making a billion dollars, as well as Oppenheimer – which also won Best Picture at the Oscars.

The now legendary director was coming off the success of Memento when he made Batman Begins and had yet to direct many of his classics such as Inception or Interstellar.

When signing on for Batman Begins, the origin film starring Christian Bale as the caped crusader, Nolan had yet to agree to their being a full trilogy.

Whilst he took a ‘one film at a time’ approach, he stated from the beginning that three is the maximum he’d be willing to do, and has since spoken about whether he would come back.

Christian Bale starred as Bruce Wayne in the film (Warner Brothers)

Many will be shocked to find however that Nolan wasn’t even the first choice for the film.

Darren Aronofsky, the director behind Requiem for a Dream, was the first choice to helm the rebooted version of Batman, with Warner Brothers taking an eight-year gap between the disastrous George Clooney led Batman and Robin and Batman Begins.

Aronofsky was set to direct a script he co-wrote with legendary comics writer Frank Miller. This script, however, was R-rated, something Warner Brothers refused to go for.

Instead, they brought in David Goyer to write a script with Christopher Nolan, insisting that it had to be PG-13.

Several of Nolan’s earlier films were rated PG-13, with Oppenheimer the only recent outing of his to receive an R Rating.

Speaking on CinemaBlend’s ReelBlend podcast about the fact they had to keep to a PG-13 rating, specifically about the second film The Dark Knight, Nolan said: “When we were making The Dark Knight, for example – which feels like an R-rated movie – there was a certain amount of negotiation and editing that had to happen to secure the PG-13 rating.

“Which is often the case with films that are edgy, PG-13 films.

We almost didn't get Christopher Nolan's Batman vision (Warner Brothers)

“But those are films that you go into with the studio knowing full well that that's the rating you're aiming for.

"You're aiming for that audience, that breadth of audience.”

He revealed you have to ‘change things to make it work’ with edgier PG-13 films and be clever with ‘implication’ and ‘how you present violence in action scenes’.

The Dark Knight Rises quite famously almost received an adult NC-17 rating until the director cut a brutal death scene.

To say it paid off is an understatement, with the three films being some of the most successful of Nolan’s career, and arguably the most beloved Batman movies ever made.