We know what we know about the Viking Age primarily from two sources: writings of the day (or soon thereafter) and archeological finds. The early primary sources about the Vikings were predominantly written by Christian clerics who made obvious efforts to demonize them because Christian monasteries were the primary targets of the first raids.
The first recorded attacks at Lindisfarne in 793 A.D. and at Noirmoutier in 799 A.D. set a precedent for the relationship between Christendom and the pagan north. The initial violence between the years A.D. 793 and 835 occurred peripherally, meaning it remained contained to coastlines. This is the period that is most romanticized in popular culture-rugged bands of marauders making sudden appearances to sack and loot monasteries for their silver.
The authors of the Anglo-Saxon Chronicle described the attack on Lindisfarne thusly: “In this year terrible portents appeared over Northumbria, and miserably frightened the inhabitants: these were exceptional flashes of lightning, and fiery dragons were seen flying in the air. A great famine soon followed these signs; and a little after that in the same year on 8 [June] the harrying of the heathen miserably destroyed God’s church in Lindisfarne by rapine and slaughter.“
Historians have several hypotheses on what began the Viking Age. The most pervasive and accepted of the hypotheses, or at least the one that is most commonly regarded as a root cause, is the change in climate that occurred in the early middle ages, which warmed the weather in Northern Europe and caused a rapid increase in population unusual for Scandinavia. This in turn led to overpopulation and when the weather cooled again, the land could no longer feed everyone. From this point, the need to leave and raid became a matter of survival.
Most, if not all, historians draw upon a combination of several hypotheses, each a part in the larger picture. These range from territorial disputes to diplomatic tensions with neighbors, and nearly all of these factors seem to have played a part. Yet most of these factors were ongoing trends, akin to Europe on the eve of World War I. It was all ready to boil over, and all the situation needed was a catalyst. The questions therefore becomes: what event acted as the catalyst for the Viking Age?
In 792 A.D. the Emperor Charlemagne was just wrapping up his conquest of modern day Poland when the Saxons, under the leadership of a man named Widukind, rebelled against him. Charlemagne’s response was swift and bloody. During their battle near the Elbe River, the Franks took 3,000 prisoners. To teach the rebels a lesson, Charlemagne ordered the prisoners be baptized in the Elbe, where the priests recited their benedictions, and the Frankish soldiers held their victims underwater until they drowned.
The event, thereafter dubbed “The Massacre of Verdun” was no more gruesome than many of the other acts committed by the Carolingians in the name of their god, but this event was different. Widukind, the leader of the Saxons, was brother in law to the king of the Danes, Sigfred. News of the massacre undoubtedly reached his court, and as such would have (and this is conjecture) deeply angered them. It was yet another brutal, violent display of power by Charlemagne, the latest in a long series spanning decades.
From what historians can tell from the sources they have, Danish raids along the coast of Frisia (modern day Netherlands) intensified almost immediately, leading to an infamous raid on Dorestad, to which Charlemagne supposedly bore witness, if we are to believe the account given by the chronicler Einhart in his work Two Lives of Charlemagne. The very next year, the attack on Lindisfarne occurred, and the rest is fairly well known history. What is the proof that the Massacre of Verdun was the proverbial straw that broke the camel’s back? Admittedly, the evidence is circumstantial, but there is no doubt that the Viking Age was, in part, sparked by poor diplomatic relations with the Franks, and they may have even been the catalyst.