|And then these dudes showed up and asked what the hell|
we were doing wearing all those clothes on a tropical island.
I joke that everything I learned about quantum mechanics comes from Michael Crichton's Timeline. I might as well joke that most of what I know about history comes from historical fiction. I've learned from these books, in part, because I can't stay away from Wikipedia and my library's non-fiction collection.
For me, the best works of historical fiction are about the people you don't hear about in the history books--and it's not just because I end up questioning fiction with famous protagonists so much that I can't get into the story. When I finished reading Connie Willis' Blackout and All Clear, then went back to her dedication to all the people on the home front. That dedication was so moving the second time around that, when I closed the book I had to just sit there for a long minute and think about the actual people who endured and fought the Second World War. That's what great historical fiction does (even if those books have time travelers).