For better or worse, Americans gain a significant and increasing percentage of their knowledge of history from movies.
Learning history from movies can be helpful, but there is an even greater need for critical thinking than when learning from books.
Certainly, history books can be loaded with "spin" - history is told in a certain way to advance the author's political agenda.
But movies are subject to double spin - they have the same political spin as books, and then a second layer of spin is added because the movie needs to be entertaining. Movies may contain historical inaccuracies, not only beause of the filmmaker's political views, but also because the filmmaker may change the events simply to make them more entertaining. People going to see movies demand to be entertained, but they don't care if they're accurately informed. Recent films about the Trojan War and Alexander the Great demonstrate this sufficiently.
The informed viewer can exercise critical thinking by watching two different films about the same historical events.
Cleopatra, for example, was the subject of a 1963 film by Elizabeth Taylor, and a 1934 film by Claudette Colbert; view them both, and you'll hopefully "cancel out" the spins of the various screenwriters.
Likewise, Marie Antoinette was the subject of a 1938 film by Norma Shearer, and a 2006 film by Kirsten Dunst. Both are informative.
In either case, it helps to read even a brief, half-page encyclopedia article about the people and events concerned. Reading even a little before the film not only makes you understand it better, it helps you to enjoy it more, because you understand.
More recent events in film include the movie "End of the Spear" (made in 2005), which depicts the murders in the Amazon Basin of several Americans; the same situation was filmed as "Beyond the Gates of Splendor" in 2002. Both films seem fairly accurate.
