The early Dark Ages were much lighter than we give them credit for, but they were also much darker than we give them credit for. Because a part of Europe was "Pagan" and had Light, whilst another part had fallen to the Christian aggressors and thus had only Darkness. The peoples in Northern Europe, who had not yet been exposed to the Christian wave of cultural destruction and genocide, thrived during the early Dark Ages.
There was even much gold in Northern Europe at the time, and they got their gold from the Romans, probably just like the Vikings got their gold from the Christians a few centuries later. Because the Viking Age - the defense war against the aggressive, murderous and maniacal Christians - started much earlier than we normally think. Even the "barbarians" sacking Rome in late Antiquity were in reality fighting against the genocidal, internationalist madmen of Rome, and should be counted as the first (land based) "Vikings".