The thing that most attracts me to historical fiction is taking the factual record as far as it is known, using that as scaffolding, and then letting imagination build the structure that fills in those things we can never find out for sure.
Both my mum and dad were great readers, and we would go every Saturday morning to the library, and my sister and I had a library card when we could pass off something as a signature, and all of us would come with an armful of books.
You can't write about the past and ignore religion. It was such a fundamental, mind-shaping, driving force for pre-modern societies. I'm very interested in what religion does to us - its capacity to create love and empathy or hatred and violence.