Jolie explained at the premiere of In the Land of Blood and Honey that she was able to better understand the causes of the Bosnian War while spending time in the region.
"Bosnia has always been a situation and a conflict that I'd never been completely able to understand, so it was also a chance for me to dip deeper and learn and educate myself on the concept," the star revealed to Access Hollywood.
She added: "It was just the combination of 10 years of travelling and the frustrations and all the questions in my mind. Trying to get those questions out into the world and try to search for an answer."
Jolie went on to say that while directing In the Land of Blood and Honey brought her many intellectual challenges, she most enjoyed not being pampered like she is when acting.
"It was wonderful. I never had to go to hair and make-up and I got to hang out with the crew," Jolie said. "I got to shine the spotlight on extraordinary actor… Zana [Marjanovic] is the movie star tonight. She is so deserving and so extraordinary - it's thrilling."
In the Land of Blood and Honey, which stars Marjanovic and Goran Kostic, is released in US cinemas on December 23. Details of a UK release are yet to be confirmed.
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Watch a trailer for In the Land of Blood and Honey below: