Just wondering for anyone familiar with medieval history. After the fall of the Roman Empire till around the 15th or 16th century (correct me if I'm wrong, I'm just guesstimating) is described as the Dark Ages, or the fall of enlightenment. Was this for all of the known world or just Europe? In terms of fighting and constant warfare that seemed worldwide. But it seems that the North African and Middle Eastern civilizations continued steadily- much of their sciences and advanced aspects of civilization (that was a combination of truly local advances and those of the Romans) absorbed by the Mediterranean and European Civilizations during the Crusades.