There are many views on how accurate “Kingdom of Heaven” really is to history. Some people believe that it is very far from the truth and others tend to believe that for Hollywood it is very accurate. 
It is a discussion that will come up for most any hitorical based movie. No one can tell you for fact every little detail that did and didn’t happen, but that doesnt mean they wont try.
Most of the movie takes place in the deserts of the Holy Land but there are a few historically accurate scenes that tak place elsewhere. There is a small scene that shows Balian sailing from France to the Holy Land across the Mediterranean. During his journey there is a storm which is very realistic. The hazard of sea travel across the Mediterranean is true to the era. Richard the Lion Heart dealt with stormy seas and shipwreck on the eastern portion of the Mediterranean coast.
Through out the movie there are scenes that show the Muslims as being incapable of technology when this is very untrue, in fact they were the most advanced of the two religions. There is a scene where Saladin is talking to King Baldwin about Baldwins being sick. Saladin offers up his best physicians to Baldwin, showing they had the better medicine. In another scene Balian finds a way to bring water to Ibelin and the natives are shocked. It makes it look as if the natives had no way to bring water to their land until the Christians showed up.
The main portion of the movie that causes the most controversy is the final battle for Jeruslalem. There are a few things wrong with this battle. The use of Flaming arrows and boulders, while known to be used, is said to have not been used in this battle. 
Just before the final day of fighting, Balian is said to have knighted every man able to wield a sword. In the movie it is portrayed that he Knighted every man in the city, when in reality it was only a few hundred men. At the end of the battle Balian and Saladin discuss terms. Balian says he will destroy the whole city and murder every Muslim inside unless Saladin lets them leave without harm. This did in fact happen. Saladin aloud the people to buy their way out, as long as they were gone by the next day. When Balian returns to his soldiers they all cheer as if the battle was just bloodshed for nothing. In real life the people were devastated and they were all in mourning over their loss. Even the Pope was in mourning until his death.
All though this movie may not be totally accurate it is still a well made film that is meant to be entertaining. Not every movie based on actual events is going to be 100%. That doesnt mean we have to point out every single flaw in the movie.
