For the "Barbarians” had nothing whatsoever to do with the disappearance of Classical Civilization: The great cities of the Empire, both in the West and the East, continued to flourish during the fifth and sixth centuries. The "Barbarian” kings, we now know, actually fostered Classical learning, and wasted no time in becoming completely Romanized themselves. They minted gold coins stamped with the image of the Emperor in Constantinople, and regarded themselves as functionaries of the Empire. The cities built by the Caesars continued to flourish, and there was even a great deal of new building and expansion. By the beginning of the sixth century Classical civilization had spread into the formerly barbarian regions of Ireland, Scotland, and eastern Germany; and the works of Homer and Virgil were now discussed in the rocky crags of Ireland’s Atlantic coast and the remote isles of the Hebrides.
And intellectual life flourished among the cities and towns of Europe: authors such as Boethius and Cassiodorus were thoroughly steeped in the learning of Greece and made important contributions of their own. The former is regarded as one of the greatest minds of antiquity, a man whose all-encompassing genius sought to reconcile the thinking of Plato and Aristotle.
There was, therefore, no "dark age” in the fifth or sixth centuries.