A minor point: the so-called "Dark Ages" (not great terminology, in my opinion), are usually taken to be the span of time between the fall of the Western Roman Empire in the 5th Century to around AD 1000. Anything after the 11th Century (and until the early 16th Century) is said to be "Medieval" or "Middle Ages", and not the "Dark Ages".

Anyways, not discouraging further discussion, but take a look at our Dark Ages FAQ, including our AMA - Late Antiquity/Early Medieval era circa 400 - 1000 CE, aka "The Dark Ages". A lot of your questions are answered there. If you have any further questions however, feel free to ask them here. :)