Later they showed that westward - expanding Huns carried with them plague that was basal to the Justinian plague .
Are thus the likely source of this plaque entering into Europe with the devastating consequence of killing millions as a result .
Later they showed that westward - expanding Huns carried with them plague that was basal to the Justinian plague , and are thus the likely source of this plaque entering into Europe with the devastating consequence of killing millions as a result .