So thanks to the responses I think I'm on the right track. Definitely moving from conspiracies to other causes:
Low resources due to high population and poorer citizen's starving and having their crops and livestock heavily taxed on top of that once shortages shortages start to affect the cities.
Thanks all who replied! Very good advice here.
I think I definitely need to simplify things a bit and brush up on a few history lessons, as well as develop my world a little more before I start freaking out over this.
Hell there! I recently started a new writing project with a partner and we're still in the very beginning stages of planning a graphic novel fantasy adventure, set in medieval time. There's been one problem that I can't seem to get around or find a solution to, maybe a few minds on here can...