Historical fiction is a very interesting sub-genre of the fiction novel. The time in the past which the story is set in is real, but the characters don’t necessarily have to be. Some authors take a real character and apply poetic license to it and make the character more layered than they actually were.
Every reader is going to have their own personal favorite author of this sub-genre because different readers like different styles. One thing the readers all have in common though is their love of history. This is why it’s very important for the author to keep things as historically accurate as possible.
The sky is the limit, really, as to how many different directions an author can go with this type of novel. If you love to write books, you have to try writing at least one novel of this sort. It’s challenging.