Climate change and a major pandemic may have been the backdrop for a “significant economic downturn” on the edge of the Byzantine Empire in the mid-sixth century CE, archaeologists in the Middle East have suggested.
Tracking the rise and fall of viticulture (wine-making), a team of Israeli archaeologists have said commercial wine sales appeared to plummet in the years following plague and global cooling caused by an enormous volcanic eruption.
The first wave of what later became known as the Black Death spread throughout the Byzantine Empire and beyond, and became known as the Justinianic Plague, after Emperor Justinian, who contracted the deadly disease but survived.
While the plague has become associated with the medieval period of European history when tens of millions died, its earlier waves also inflicted high mortality, and brought a broad range of socio-economic impacts.
At the same time as the Justinianic Plague’s worst effects were being felt, the planet was in the grip of the coldest decade of the last two thousand years.
A cataclysmic volcanic eruption is known to have occurred in late 535 or early 536CE.
It is not known exactly where the volcano erupted, but tree ring analysis, ice cores and geological sulphate deposits all confirm written accounts of short-term global cooling.
The Byzantine historian Procopius wrote of the dramatic change in climate in 536 AD in his report on the wars with the Vandals. He said: “During this year a most dread portent took place. For the sun gave forth its light without brightness … and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear.”
Despite the evidence of both the volcanic eruption and the early wave of bubonic plague, scholars still disagree on the extent of the socio-economic upheaval that resulted.
The Israeli archaeologists said: “This scholarly debate is unsurprising considering that even today, leaders and policymakers around the world differ on the severity and correct response to Covid-19, not to mention climate change.”
But they added: “One reason that hindsight is not 20-20 when it comes to ancient plagues is that ancient reports tend to exaggerate, or under-represent, the human tolls, while archaeological evidence for the social and economic effects of plague are very hard to find.”
The new research focused on viticulture in the middle of Israel’s arid Negev desert, and sought to discover when and why the agricultural settlement of the Negev Highlands was abandoned.
Agriculture in this area of desert was made possible through rainwater runoff farming which reached its peak in the Byzantine period, as seen at sites like Elusa – which was famous in the fifth century for its wines – and the ancient cities of Shivta and Nessana.
However, despite many well-preserved architectural features of the ancient sites, the research teams discovered even more compelling evidence about life during that period in an unexpected place: the rubbish heaps.
“Your trash says a lot about you,” said Professor Guy Bar-Oz of the University of Haifa.
“In the ancient trash mounds of the Negev, there is a record of residents’ daily lives – in the form of plant remains, animal remains, ceramic shards, and more.”
“We excavated these mounds to uncover the human activity behind the trash, what it included, when it flourished, and when it declined.”
One of the key discoveries was of grape pips. The other was of amphoras – pointed-bottomed clay pots used for transporting wine and other liquids.
For the present study, nearly 10,000 grape seeds, wheat and barley were retrieved and counted from 11 rubbish mounds at three sites.
“Identifying seed and fruit remains is a unique capability of our lab,” said archaeobotanist Professor Ehud Weiss.
“It relies on the Israel National Reference Collection of Plant Seeds and Fruit held in our lab, and on years of experience in retrieving, processing, and analysing plant remains from sites of all periods in Israeli archaeology.”
One of the researchers’ first observations was the high numbers of grape seeds in the ancient rubbish tips. This finding fit well with previous scholars’ suggestions that the Negev was involved in export-bound viticulture.
Byzantine texts laud the “vinum Gazetum” or Gaza wine as a sweet white wine exported from the port of Gaza throughout the Mediterranean and beyond.
This wine was generally transported in a type of amphora known as “Gaza jars” or “Gaza wine jars”, which have been found at sites throughout the Mediterranean.
In Byzantine Negev rubbish mounds, these Gaza jars are found in high quantities.
Daniel Fuks, a PhD student in the Martin (Szusz) Department of Land of Israel Studies and Archaeology at Bar-Ilan University, and who led the study, said: “Imagine you’re an ancient farmer with a plot of land to feed your family. On most of it, you plant cereals like wheat and barley because that’s how you get your bread.
“On a smaller part, you plant a vineyard and other crops like legumes, vegetables and fruit trees, for your family’s needs.
“But one day you realise that you could sell the excellent wine you produce, for export, and earn enough cash to buy bread and a bit more. Little by little you expand your vineyard and move from subsistence farming to commercial viticulture.
“If we look at your trash and count the seeds, we’ll discover a rise in the proportion of grape pips relative to cereal grains. And that’s exactly what we discovered: A significant rise in the ratio of grape pips to cereal grains between the 4th century CE and the mid-6th century. Then suddenly, it declines.”
Furthermore, with Dr Tali Erickson-Gini, an expert in ancient Negev pottery, the team investigated ratios of Gaza jars in the rubbish mounds, and found the rise and fall tracked those of the grape pips.
The researchers concluded that the commercial scale of viticulture in the Negev region, as seen in the grape pip ratios, was connected to Mediterranean trade, attested to by the Gaza jar ratios.
The study also suggests the volcanic eruption, which was known to have led to drought in Europe, may have increased precipitation, possibly including high-intensity flash flooding, in the southern Levant, damaging local agriculture.
Professor Bar-Oz said: “It appears that agricultural settlement in the Negev Highlands received such a blow that it was not revived until modern times. Significantly, the decline came nearly a century before the Islamic conquest of the mid-seventh century.”
Two of the most likely triggers for the mid-sixth century collapse – climate change and plague – reveal inherent vulnerabilities in political-economic systems, then and now, the authors said.
“The difference is that the Byzantines didn’t see it coming,” said Mr Fuks.
“We can actually prepare ourselves for the next outbreak or the imminent consequences of climate change. The question is, will we be wise enough to do so?”
The research is published in the Proceedings of the National Academy of Sciences (PNAS).