Okay, here goes:
1) The first issue that must be addressed is the meaning of the term "historical fiction." Why is it "historical"? Simply because the story takes place in the past? I don't think that's sufficient.
A. Because the story encompasses or depends upon historical events? Because the characters are either actual historical personages or encounter such in the story. Maybe, but are these enough?
B. Because the world of the story, as portrayed, is as near to historical reality as the author can make it? That seems to be what is being suggested.
C. Because the characters in the story are created specifically as characters of a given period. I think this is critical. In fact, I think it overshadows the rest. A Roman patrician didn't act like a Fortune 500 executive. His world view was different. His knowledge base was different. His culture was different. Trying to capture the essence of what it meant to be such a person would be my goal.
And when fashioning the world of the story, what is more important? Having 17th century Vienna townspeople act and respond like 17th century townspeople, or making sure a description of the material used to stuff a mattress in that period is historically accurate? And make no mistake, the latter issue has been the subject of intense research for some social historians.
No doubt, anyone who aspires to write good historical fiction must do research. And no doubt, good research applied to a story can make it more believable, so please don't think I'm eschewing the importance of such. Still, there is a finite limit to research, and the possibility of an error exists. Always.
2) When it comes to changing/manipulating events and the like for the purposes of the story, I think it obvious that changing critical events in terms of specific elements, placement, time frame, and outcome can lead to a change in genre. Introducing AK-47's into the Civil War for the purposes of a story would suggest a genre other than historical fiction. Once "what-if" becomes a meaningful question, history is no longer the dominant concern.
However, there is a deeper issue here. The fact is that historical fiction is fiction, by definition. Creating a character and having that character actively interact in historic events, like a Greek playwright who is a friend and competitor of Aristophanes, is not real. Facts are being manipulated. So too, having a character that fights in the such-and-such infantry division at the Battle of the Muse-Argonne, whose actions impact the event, even thought the outcome is unchanged, is creative license. Making sure the correct PX watch is being worn by the character does not undo this fiction that is his very existence.
3) In the fields of historical inquiry, the ascension of social history suggests, to me, a desire by many to never be just "close enough." And that's all well and good. At least, until the effort for mundane accuracy leads to a failure to appreciate/understand history in a larger context. I'll give a specific example: The Return of Martin Guerre by Natalie Zemon Davis. It's a wonderful story, though it is presented as mostly history when it really is fiction, with much to be admired. However, I would humbly suggest that the author stumbles badly, by introducing modern concerns into the patterns of the past. Getting your mundane facts right is not a sufficient condition for getting your history right. Not by a long shot.
4) From a personal perspective, I want a book of fiction to entertain me or at least interest me. And I love history. And I know history. Educating me as well can be a great benefit, but I don't see it as primary. Attention to detail is great and, as I said, it can make a story more believable. But there is a limit, I think. There must be.
Okay, let me have it.
