Stealth SF

The Dragon Waiting has got me wondering whether any fringe alternative-universe novels have ever been written which appear at first to be historical novels, but where, in a relatively late development, a historical event suddenly happens quite differently from how the reader expects?

One approach would be to make the story primarily about the event itself rather than its consequences -- an account of the victory of the Spanish Armada, for example. Another would be to examine the more personal effects of alternative experiences (as Sliding Doors did for example), but in terms of a well-known historical figure -- a novel about Abraham Lincoln where he ducks, for instance.

Can anyone think of any candidates?

Edit to add: I should specify that I'm not talking about novels of time-travel where visitors from the future change history -- I'm aware that there are lorryloads of those. I'm thinking of stories with no "SF element" except that a historical event happens differently.