The correct answer is - historical novel.
The historical novels are very important and valuable assets for the historians to gain context about a certain historical event or to figure out what was the perception of the world and behavior back then. On the other side, the historical novels should never be taken as evidence because they are highly unreliable due to the fact that most of the authors were subjective more often than not, so they were giving their own perception of things and happenings most of the time, not the objective picture of them.