Call it a coincidence, but before MTWII I started reading 'the accursed kings' by Maurice Druon (well, I read it in French).

Any MTW player is bound to love it, it is all about kings, arranged marriages, killing the pope and get one's cardinal elected, poisoning kings...

More precisely, the history of the end of the Capetian kings, from Philip IV the Fair who wiped out the templars, till Charles IV his third son, and the premises of the 100 years war.