I think what draws me most to historical fiction is the glimpse into how people lived in other eras. I have always found that fascinating. Social mores, fashions, even food! I recently completed a course on royal food and feasting from the Tudor to Victorian eras.
I enjoy the process of researching a story, and I love the richness of detail that comes from doing that work. I’m one of those rare birds who treats research as a treasure hunt rather than a chore; the hardest thing I experience is limiting how much research I do, because it is far too easy to go down a rabbit hole and never do any writing!
It took me four years to write each of the full-length Phantom novels (In The Eye of The Beholder and In The Eye of The Storm, respectively) because I spent so much time doing research; the rabbit hole for the second one was the modern art movement in Paris.