The answer is in the name. Applied History. The best fiction is based on reality. I've looked up all sorts of weird stuff for my contemporary novels, including how to grow organic popcorn (and what the best varieties were), the largest contiguous plots of "wild land" in England and how they were protected, and current methods of treating PTSD including fringe research. Being able to create a good research question is most of the solution to answering your research problem.