Brad Pitt appeared at the London premiere for his newest film 'Allied' this week, where he talked about where the story came from and what drew him to the project in the first place. It's a Second World War based thriller directed by Robert Zemeckis and co-starring Marion Cotillard as his onscreen love interest.

Brad PittBrad Pitt says there's truth behind 'Allied'

The Oscar winning superstar is no stranger to World War II style films having previously starred in Quentin Tarantino's 'Inglourious Basterds' in 2009 and David Ayer's 'Fury' in 2014. This time he takes a role away from the frontline as a Canadian intelligence officer named Max Vatan, who marries a French Resistance fighter named Marianne Beausejour. When his wife is later accused by Vatan's colleagues of being a German spy, he is urged to eliminate her, but instead he sets out to prove her innocence.

According to Brad, the story isn't altogether fictitious; indeed, it's apparently based on something that actually happened in screenwriter Steven Knight's family in the early 40s. 'He actually told me this story years ago', Brad explained on the red carpet at the London premiere. 'It was loosely based on an event in his family lineage. It sounded like a good story and I wanted to try an old school romantic thriller.'

Watch the trailer for 'Allied' here:

Brad and Steven are set to reunite again soon as the latter has been announced to pen the script for 'World War Z 2'. David Fincher is rumoured to be directing the movie, having also previously worked with Brad on such movies as 'Se7en', 'Fight Club' and 'The Curious Case of Benjamin Button'. 

Brad's next movie is another war film called 'War Machine', but this time focusing on America's war with Afghanistan. It's a satirical exploration of the people running the campaign, with Brad playing General Dan McMahon; a character based on real life Commander General Stanley McChrystal.

'Allied' arrives in theaters today (November 23rd 2016).