I have had, for several years, an idea for the book I'd like to write next. It was inspired by repeated readings of a lushly illustrated kids' picture book, a retelling of one of the classic fairy tales. Only, if I do it the way I want to do it, many readers might read the book and not recognize the core story (no, I'm not going to tell you what story it is). My thought was to set the story in medieval Italy. This causes a certain tangling up of terminology: while of course Italy existed during the years all the other nations in Europe were having a middle ages, as I read and research I find it hard to pinpoint that era in Italy. There's the Renaissance, and before that the endless decline of the Roman empire and the splitting up of the Empire in to smaller factions, and many invasions by other parties. You can point your finger at France or Germany or England and say, there, that's the middle ages. It's harder in Italy.
One thing that sold me on the time and place was Trotula di Salerno, an early and wildly influential gynecologist in the 13th century who was a teacher at the medical school in Salerno--and a woman. Her texts were still being used by doctors as late as the 18th century, and while some of her information is decidedly of the "you puts a knife under the bed to cut the pain" variety, other of it is remarkably sage. Her name survives in some versions of "Jack and Jill": "then off Jack got and off did go as fast as he could caper/to Old Dame Trot, who patched his nob with vinegar and brown paper." I really want my protagonist to be one of Trotula's students. And of course, I'd love to be able to go to Italy to scope out the terrain.
Unfortunately, Salerno is one of those towns that was pretty much flattened during World War II. While the climate and the physical feel of the city is probably unchanged from 900 years ago, there is very little of the medieval university, or the medieval city, to be found.
So I'm reading up on medieval gynecology and Italian history. I may wind up with a book no one wants to buy (what? another damned Italian fantasy? pfui!) but it won't leave me alone, and the books that follow me down dark alleys are generally the ones I want to write.