In this year (793 AD!) terrible portents appeared over Northumbria and sadly affrightened the inhabitants: there were exceptional flashes of lightning, and fiery dragons were seen flying in the air. A great famine followed soon upon these signs, and a little after that in the same year on the ides of June the harrying of the heathen miserably destroyed God's church in Lindisfarne by rapine and slaughter.
And so it began. This reference in the Anglo-Saxon Chronicle - 9th century document considered the most important source for the history of England in Anglo-Saxon times - is the first mention of the arrival of Viking raiders to the British isles.
Soon, the prayerbooks of the time included this prayer: A furore Normannorum libera nos, Domine. Translated: "From the fury of the Northmen deliver us, O Lord." These Vikings were fearsome and destructive folks indeed.
But, in one of the fascinating transformations in European history, these same Vikings were to become Lutherans - over time. First, they pillaged the monetaries of Ireland, took some territory as their own, or enslaved the inhabitants, even kidnapping them back across the North Sea. But along the way, these oppressors heard the Gospel of God's Grace from the people they tormented. And that seed took root, grew, multiplied and eventually bore fruit. The Vikings came to faith in the Jesus of their captives, and the rest is history. They even signed on with the evangelical faith of their German neighbors after God used Luther for a season of renewal there.
Granted, it took about 800 years but under the influence of the Gospel, the Vikings were transformed from death-dealing mauraders to reliable neighbors. Life was better for all. This is what God does through the Gospel over time.
Sadly, the influence can flow both ways. A few more centuries and after a migration to America, these Vikings turned Lutherans have now produced the likes of Nadia Bolz-Weber, a modern day pastor/prophet of expressive individualism.
So stay faithful and pray in every generation. Let the Spirit have His way and bear fruit in every life. But know that the Gospel has transformative power.
For Further Reference:
The Fury of the Northmen | Christian History | Christianity Today
Viking Answer Lady Webpage - Origin of the phrase, 'A furore Normannorum libera nos, Domine'