 Complete the following phrase:  Various modern scholars of history and geography regarded the Vikings and their descendants as Gog and Magog, since the unknown group from Scandinavia had made their sudden and considerable entry into the history of Europe. Viking travellers and colonists were seen at many points in history as violent raiders. Many historical documents suggest that their conquests of other territories was retaliation in response to the encroachment upon tribal lands by Christian missionaries, and perhaps by the 