Emerikol
Legend
Thanks for the reference it looks really good. I put it on my wishlist but I may pick up the whole set soon.If you want a wonderful (and giving the author's credentials: accurate) description of how the various royals, nobles, merchant houses, states and merchant leagues in Europe interacted during the late Middle Ages (and if you can spare the time to read eight lengthy volumes), I highly recommend Dorothy Dunnett's House of Niccolo series, about the rise of a merchant and banker from Bruges in the 1460s.
I think for me creating these societies has been a lot of fun and I definitely mix it up. If you create really compelling NPCs your world will be more compelling for your PCs. Great NPCs play themselves to a degree just like great characters in a novel sometimes take over the story from the author.