By Tenaya Jorgensen
As an Environmental Historian, I am keenly interested in how humans have responded to climate pressures and weather extremes in the past, and what we can learn from these responses today. One aspect of my doctoral research compares periods of violence against temperature and precipitation during the early Viking Age, c. 790-920. While the Norse are rarely mentioned in the years leading up to their first raids, it is important to investigate if and/or how the climate varied in Scandinavia and the rest of Europe prior to the earliest Viking attacks. Could the climate have played a role in kickstarting the Viking Age?
Scientists warn that more extreme weather may result in famine, and worsening climate conditions have been shown to influence production levels. In Kenya, the majority of famines are triggered by drought. Successive dry years have resulted in crop loss, reduced harvests, emaciated livestock, and human hunger and death. Even when the local population is able to produce, store, and access enough in non-drought periods, they are unable to build up a large enough buffer to cushion crop and income against the next period of drought and famine.
But, the success or failure of the crop yields relies on both exogenous and endogenous factors: external (exogenous) conditions, such as extreme weather and climate changes, cannot be considered independent of socioeconomic, internal (endogenous) conditions. Food shortages stem from a complex network of political, social, economic, and biophysical factors. For example, in 2017 the famine on the Horn of Africa was exacerbated by armed conflicts, which made distributing imported food goods throughout the population nearly impossible.
Could drought have been a catalyst for the first Viking raids?
The first Viking raid is usually attributed to the 793 attack on Lindisfarne. The entry in the Anglo-Saxon Chronicle, a near-contemporary chronicle for the early English kingdoms, reads: “…Shortly after, in the same year, on the sixth day before the ides of January, the woeful inroads of heathen men destroyed god’s church in Lindisfarne island by fierce robbery and slaughter.”
This, of course, is not the whole entry, but the rest has often gone unremarked: “This year came dreadful fore-warnings over the land of the Northumbrians, terrifying the people most woefully: these were immense sheets of light rushing through the air, and whirlwinds, and fiery dragons flying across the firmament. These tremendous tokens were soon followed by a great famine. Shortly after, in the same year, on the sixth day before the ides of January, the woeful inroads of heathen men destroyed god’s church in Lindisfarne island by fierce robbery and slaughter.”
793 sounds like an extremely difficult year for the Northumbrians, no less so because of the Viking raid, but the famine needs further examination.
I wondered if any of the other Western European contemporary sources recorded this famine as well. The Frankish chronicles do record a famine at this time, though it appears to have begun several years prior. In 791, the Annales Mosellani state that a famine began in Francia. The source mentions it again in 792, and by 793 it was described as a “great famine.”  This famine was so severe that Adrian Verhulst suggests that it led to both the Council of Frankfurt fixing grain and bread prices in May 794, as well as to the Frankish monetary reform of 793-94, which saw the denier being linked specifically to the price of bread.
But the famine may have spurred public works beyond bread-price and monetary reform. In 793, Charlemagne oversaw his fossatum magnum, a canal that linked the Rhine and the Danube rivers. Janet Nelson has argued that the canal was the product of a “series of acute harvest shocks,’ which necessitated the need to ship grain and other food-stuff from famine-free zones to famine-affected areas quickly and efficiently. Such construction could be indicative of a number of famines and food-shortages, as Charlemange’s fossatum magnum was a serious governmental work.
Comparing the written sources against natural archives
Historians now have easy access to sources within the paleoclimatic sciences. Freely available online is the Old World Drought Atlas (OWDA), which uses dendrochronology to recreate hydroclimatic variability for a year-by-year assessment for much of Europe.
I first checked Western Europe and Britain for evidence of drought from 791-794, and these areas do indeed reveal a distinct lack of precipitation during the summer months of this period. This proxy data matches the contemporary chronicles, and it would appear that the Norse conducted their first raid during a time of widespread drought.
But correlation is not causation, and while there appears to have been drought in Scandinavia as well, we do not have contemporary records from the Norse to confirm that they set out due to a disruption in food supplies, or if they had even suffered from famine at all. The Norse may have had sufficient mitigation measures in place to keep food supplies stable.
What would the climate have looked like for the generation leading up to the Viking raids?
For this reason, I decided to push the study of precipitation levels back to 770, which would allow for a 25-year study of the climate of Northern and Western Europe from 770-795. In this way, I sought to confirm if precipitation levels were stable in the years leading up this drought; in particular, I was curious whether Scandinavia suffered under climate pressures that could have led to a break-down in mitigation measures.
The OWDA reveals that precipitation levels were well below average for this period. Within Scandinavia, there are only three years that rise at- or above-average precipitation levels: 771 and 780-781.
Europe and Britain also appear to suffer from below-average precipitation levels during this entire twenty-five-year period. There are periods in which precipitation levels rise above normal, but these twenty-five are marked by less-than-average rainfall during the summer months. Drought is mentioned the Royal Frankish Annals in 772, and famine is recorded in 779 in the Annales Mosellani.
Given the long periods of drought, and several noted famines, is it possible that this particularly dry period was a factor in the beginning of the Viking Age?
More research ahead
Undoubtedly, the reasons behind these first Viking raids are varied and numerous. Yet, previous research has previously overlooked or dismissed climatic factors, perhaps in fear of falling into the trap of environmental determinism. Even within climate and environmental history, there is more to study, including temperature, a known Solar Particle Storm in 774-775, and agricultural practices of the time.
My research proposes that a generation of drought led to instability in the food supplies of Western and Northern Europe, which no doubt impacted, and were impacted by, other geopolitical factors. Ultimately, the famine of 791-794 should be considered as one of many catalysts for the earliest Viking raids.
Tenaya Jorgensen is a PhD Candidate at the Trinity Centre for Environmental Humanities at Trinity College Dublin, as well as a junior archaeological consultant for Rubicon Heritage Services Ltd. You can follow her on Twitter @tenayajorgensen, or her PhD project @VikingAgeMaps.
 Annales Mosellani (703-797), ed. J.M. Lappenberg, SS 16 (1859), 494-499.
 Adrian Verhulst, The Carolingian Economy, Cambridge Medieval Textbooks, (Cambridge: Cambridge University Press, 2002), 118.
 Janet Nelson, “Charlemagne’s fossatm magnum: Another Look,” in Academica Libertas: Essais en l’honneur du professeur Javier Arce – Ensayos en honor del profesor Javer Arce, eda. D. Moreau and R. Gonzalez Salinero (Turnhout, 2020).
Cover Image. The 9th century Viking Domesday stone at Lindisfarne, now displayed in the site museum (2007). Photo by Wendy North, 19 April 2007, (https://www.flickr.com/photos/primarygeography/4223117304/in/photostream/). Available in the public domain.
Figures 1, 2, 3, and 4. The Old World Drought (OWDA) for 791-794 in Ireland, Britain, and Western and Northern Europe. Images created by post author using OWDA tool, September 2021. http://drought.memphis.edu/OWDA/HelpMap.aspx.