A Dark Age is not just a period in which people no longer know how to do things. The real key is that people no longer remember that certain things can be done at all.
Jerry PournelleIn any bureaucratic organization there will be two kinds of people: those who work to further the actual goals of the organization, and those who work for the organization itself. Examples in education would be teachers who work and sacrifice to teach children, vs. union representative who work to protect any teacher including the most incompetent. The Iron Law states that in all cases, the second type of person will always gain control of the organization, and will always write the rules under which the organization functions.
Jerry PournelleOf course most people underestimate the warrior characteristics of the Anglo-Saxon and Norman peoples anyway. It takes a heap of piety to keep a Viking from wanting to go sack a city.
Jerry Pournelle