One thing I've been interested by in studying this time period is what a mess the Holy Roman Empire was.
From La Wik:
Charles V revitalized the medieval concept of the universal monarchy and spent most of his life defending the integrity of the Holy Roman Empire from the Protestant Reformation, the expansion of the Ottoman Empire, and a series of wars with France. With no fixed capital city, he made 40 journeys, travelling from country to country; he spent a quarter of his reign on the road
