Then in Church History we were covering the early Medieval controversy between the Pope and the Holy Roman Emperors about whether the Emperor had the right to appoint Popes or whether the Popes had the right to appoint Emperors, which again is about whether the church or the state has ultimate authority.
And then, in my Comparative Fundamentalisms class, I was reading Marsden's brief history of evangelicalism & fundamentalism in America, and he mentioned that from the early days of the United States there were competing visions among Christians regarding the relationship of the church to the state. On the one hand was the Baptist and Jeffersonian tradition which advocated the separation of church and state since either (depending on your sympathies) the state would either corrupt the purity of the church or the church would undermine the state through it's constant tribal squabbling. On the other hand however was the Puritan (and, later, Republican) tradition which thought that the state ought to ultimately be subject to divinely sanctioned moral principles. So once again, a millenium after Charlemagne and three millenia after Samuel, we have the same basic question being raised again: can the state act independently of the church (and perhaps even have authority over it), or does the church have ultimate authority over the state.
As they say, history repeats itself. Funny how, after 3000 years, we still don't have a final answer to this question.