Balian is actually a very important, very under-acknowledged historical figure. But I think it's important that Kingdom of Heaven is not a historical movie, but rather historical-fiction. It clings to history as a backdrop, and changes identies and alliances whenever it suits the story. The interplay of politics in the medieval world means that accurate representation of characters, places, and motivations would be a BEAST to put into film, and would cut your audience down to serious students of history only. That's not something Hollywood can afford to do -- so I don't fault them for changing things. As long as it's an enjoyable film -- I'll give it props for that. I give more props for really trying to capture the mood and feel of the era, which Kingdom of Heaven did well. (As a side-note, the Extended Edition is 100 times better than the theatrical release, and I suggest everyone see it, whether you liked the theatrical release or not).