When winter came to Italy in the 6th century, people took to the hills and had to find new ways of surviving. This changed their subsistence and diet.
We know it too well in Scandinavia. If the wind blows from the west in December, the winter becomes relatively mild and wet. The winter does not “take”, we say. However, if it blows from the east, the icy and cold air from Siberia seeps into our limbs and souls, holding us in relentless grip until April or even later. Such is the weather patterns in Scandinavia and the rest of Northwestern Europe. In scientific lingo, these observations are to some extent the folksy equivalents of the North Atlantic Oscillation (NAO) patterns, usually summarised in an index used to indicate the atmospheric circulation and weather patterns caused by the difference in atmospheric pressure between the Icelandic low and the Azores high. This index tells us that when it is positive, Europe and the Eastern US have mild and wet weather, whereas Greenland, Northern Canada and Northern Russia get cold and dry. When the opposite is the case, weather in Scandinavia gets cold and dry, while temperatures in Greenland rise. In the Mediterranean, the weather gets wetter. This is excactly what happened in 6th century Europe.
Now, the exciting thing about the NAO is that it can be detected historically by using proxies such as hypolimnic anoxia in lakes, the grow-rings of trees and speleothems, the mineral formations in stalactites, which indicate the amount of precipitation through time. The other quality attached to the NAO is that as an index, it measures general shifts in the weather patterns, as opposed to more local events such as those forced by for instance volcanic eruptions. We might say that the NAO is an index, which gives us a general idea of the large-scale shifts in the weather conditions in Europe in the Middle Ages.
In 2012 a group of scientists published a historical index of the North Atlantic Oscillation from 3.200 BC up until now, based on a geochemical record from a small lake near Kangerlussuaq in Greenland. Recently, this index was used to characterise the correlation between climatic shifts in the Antiquity and the Early Middle Ages and major migratory events.
This study shows that the migratory movement of the Huns c. 375 – 420, which pushed the Goths, the Vandals, the Suebi etc. in front of them, coincided with a negative NAO-cycle, indicating that drought in eastern Europe, as well as central Asia, might indeed have caused a famine, which drove the hoards into western Europe.
Later c. 500 – 600, a corresponding climatic downturn indicates an overall worsening of climate with a cold and arid northern Europe and a corresponding wet and stormy Mediterranean. These climatic turbulences caused the significant Slavic migration into East and Central Europe, perhaps pushing the Lombards into northern Italy.
Without a doubt, these later migratory movements were acerbated by the extreme weather events, which accompanied the volcanic eruptions in c. 536 – 4 and which undoubtedly had significant effects on settlement patterns, social structures, worldviews, and artistic expressions of people on the peripheries of Europe at the end of the migration period.
“Periodic weakening of the NAO caused drought in the regions of origin for tribes in antiquity and may have created a powerful push factor for human migration. While climate change is frequently considered as a threat to sustainability, its role as a conflict amplifier in history may be one of its largest impacts on populations”, writes Lee Drake in a recent review of the Early Medieval North Atlantic Oscillations.
Erosions and Marshes in the Eastern Trentino
Recently, Paolo Forlin has published a study on how these events played out in at Valsugana in the eastern Trentino in Northern Italy. The Valsugana Valley runs from the east to the west and is bisected by several rivers. To the north runs the Lagorai mountains. Since Augustan times, a major Roman road, the Via Claudia Augusta ab Altino linked the northern Adriatic coast to first Trento and further on through the Adige valley to the Brenner pass. No wonder, people during the Roman optimum settled on the valley floor, which lies a mere 500 metres above the sea.
Archaeological excavations and fieldworks have also documented several Lombardic settlements, or at least the cemeteries featuring furnished graves with grave goods which are characterised as Lombardic (Langobardic). These settlements were located higher up the slopes than the earlier Roman villas. Together with Roman fortresses, these were abandoned due to alluvial erosions and flooding, which left the fertile grounds in the valley marshy, infertile and covered in forests. One such shift to higher ground is demonstrated by the setting of Castel Telvana, within which a Lombardic burial ground was discovered. This settlement was located on a hilltop above the old Roman fortress, Borgo Valsugana, which founded in the 1st century AD as Ausugum, a Roman encampment. Absent from the sources until the 11th century, the place faded from sight until the climate picked up again. As opposed to this, Castel Telvana offered a splendid and safe haven for climatic refugees from the valley-floor as well as the Lombard migrants in the 6th century. This settlement was in all likelihood connected with the Lombard duke, residing in Trento at this time.
Aspart of this move, new and innovative forms of cultivation and other agricultural strategies were adopted. Foremost, a more extensive pastoral economy was developed, so-called wild farming. This sylvo-pastoral economy involved the development of an agricultural regime characterised by more extensive cattle and swine-herding, so-called Alpine transhumance (Alpwirtschaft). This shift can be detected in pollen diagrams, which show a change from dense forests to more open woodlands optimal for grazing herds. Likely, this probably opened up for a more protein-rich diet among the invaders, and a less attractive menu among the dependants and slaves, based on new crops like rye, flax, buckwheat and millet. Bread became scarce, while soups and porridge became daily fare.
Castel Pergine in the Valsugana Valley. Source: Pinterest
Changes in North Atlantic Oscillation drove Population Migrations and the Collapse of the Western Roman Empire
By Lee Drake
In: Nature: Scientific Reports 7, Article number: 1227 (2017)
The Periphery during the Seventh Century: The Rise of a New Landscape within the Core of the Alps. Climate Change, Land Use and the Arrival of the Lombards in the Eastern Trentino, Northern Italy (sixth to seventh Centuries).
By Paolo Forlin
In: The Long Seventh Century. Continuity and Discontinuity in an Age of Transition. Ed. by Alessandro Gnasso, Emanuele E. Intagliata, Thomas J. MacMaster and bethan N. Morris. Peter Lang 2015, pp. 87 – 106
C4-Consumers in Southern Europe: The Case of Friuli V.G. (NE-Italy) During Early and Central Middle Ages
By P.Iacumin, E.Galli, F.Cavalli, and L.Cecere
In: American Journal of Physical Anthropology (2014) Vol 154, pp. 561 -574
The Floods of 589 and Climate Change at the Beginning of the Middle Ages: An Italian Microhistory
By Paolo Squatriti
In: Speculum (2010) vol. 85, No. 1. pp. 798 – 826
Approaches to the environmental history of Late Antiquity, part II: Climate Change and the End of the Roman Empire.
By: Michael J. Decker
In: History Compass (2017) 15:10,