Oppenheimer has become the highest grossing WWII film of all time, having raked in the big bucks after premiering three weeks ago.

The film – directed by Christopher Nolan - is based on the 2005 novel American Prometheus by Kai Bird and Martin J. Sherwin.

It follows real-life physicist J. Robert Oppenheimer, played by Cillian Murphy, who is working alongside a team of scientists to build the world's first atomic bomb during World War II.

The movie famously hit cinemas on the same day as Greta Gerwig’s brightly-coloured fantasy comedy flick Barbie, but while many assumed the two would become fierce rivals due to clashing release dates, they appear to have enjoyed a symbiotic relationship - and an incredibly successful one at that.

In fact, they both hit huge milestones over the weekend.

Universal Pictures

While Barbie passed the billion-dollar box office mark, official estimates from Universal Pictures showed Oppenheimer had made $552.9 million worldwide – in turn making it the highest grossing WWII film of all time.

Universal Pictures said it is now the highest grossing R-rated movie of this year and ‘marks the fastest a Universal R-rated film has hit the $200 million threshold domestically'.

Paul Dergarabedian, senior media analyst at Comscore, told CNN that Nolan’s hugely successful film had "an astounding theatrical run made all the more impressive by the R-rating, running time and subject matter which, in the hands of a lesser filmmaker and absent a spectacular marketing and release strategy, would have likely wound up as a mere footnote when referencing the performance of historical dramas at the box office."

Indeed, CNN reports the movie is one of only four biopics to earn more than half a billion dollars globally, alongside Bohemian Rhapsody, Passion of the Christ and American Sniper.

Universal Pictures

Dergarabedian added: “Oppenheimer… [has] become one of the most revered, talked about and successful summer movies ever to be released by a major studio,” Dergarabedian said, adding how the film ‘demonstrates the power of great filmmaking and of course a bit of unforeseeable “Barbenheimer” magic’.

Barbie, meanwhile, has been widely praised after becoming the only billion-dollar blockbuster to be solely directed by a woman.

It has also seen the biggest opening for a movie about a toy, the biggest opening ever for Margot Robbie and Ryan Gosling, and the biggest opening weekend for a film that isn't a sequel, remake, or superhero movie.

Watch Oppenheimer – and Barbie – in cinemas now.