It was so frustrating to see Anne doing Will's work for him and taking his jealousy-prompted abuse over and over. It was always, in the end, portrayed as something that came with his genius. I'm pretty sure people can be a genius in their craft and still manage to not be assholes all the time. Anne was as successful as a common-born woman could be, especially one with "foreign blood" in her, yet she set herself back with her near obsessive love for this man.
The history of the time period was probably my favourite part (and I think I could see Harper's love of Elizabeth I leaking through the pages a bit).