Working on The Falconer. Just brainstorming, which is a phase of this work I really enjoy. Everything is possible. It's like sitting down to the piano and just noodling around, following a bit of melody or a chord structure without worrying about whether I'm making a song or not.
Right now I'm messing about with the three main characters: Frederick, who will eventually win his throne as emperor; Otto, who has the throne now; and Maddig Vaychone, my antagonist.
Otto was supposed to be the antagonist--after all, he's the rival--but the more I read about Otto of Brunswick, the more he seemed like a fellow in over his head (NB: this story is based on the true story of Frederick II Hohenstaufen). I now picture him as a fellow who really should have been a minor baron. He likes to hunt, he's pretty good at fighting, he's clueless at politics, and a poor judge of character. He had an overbearing father (Henry the Lion) and is cursed with being in a family with European-wide influence. He doesn't want to be emperor, he was chosen by others, but once chosen he's determined to do his best. Which is never quite good enough (he was on the losing side at Bouvines).
Anyway, that sort of fellow just isn't going to make a good opponent for the brilliant and calculating Boy of Apulia (Fritz). So I had to come up with someone else. Someone manipulative, the real factor behind getting Otto chosen in the first place. So I made up the entirely unhistorical Maddig Vaychone, a woman who has risen to the top of the feuding, complicated network of wizard schools, temples, towers, houses, and the rest. Her goal is to have wizards rule the world, with kings being secondary to them. When Henry VI died, she saw her chance and chose Otto as best fitted for the role of obedient partner.
So it's that sort of thing right now--doing the historical reading to glean what useful biographical bits I can, getting the chronology down, and creating the suitable back story on which to build the story.