So, I watched the film Belle (2013) last night. Though there were some pacing issues in the beginning (first few scenes felt rushed, but it quickly got on the right pace), it was every bit the lush period piece I hoped it would be. But while it's based on a true story, comparing the historical details in the film versus the actual history showed quite a few glaring differences. #Nospoilers. Just an example. Let's say an event, such as inheriting an estate, takes place within 2 years of a character's life in the film; whereas in real life it took 10 years. Some of the historical characters' lives were fudged as well. One of them has an occupation in the film that they didn't have in real life. However, the occupation gets them closer to another pivotal character, and drives them towards important dialogues about slavery, law and abolition. Without this, these two characters wouldn't have met so formally. Their interaction culminates in the film's climax. My Question: I know the purpose of changing some details in Belle was to truncate the film and get to the bare bones of the plot in fewer characters....But how would one know what details to change in historical stories? How do you know what aspects of the history to sacrifice without losing the essence of the (hi)story itself?