Ancient trash heaps reveal the Plague of Justinian’s economic toll

Ancient trash heaps recently yielded some clues about how the Plague of Justinian, part of a one-two punch with volcanic climate havoc, devastated commercial farming at the fringes of the Byzantine Empire in the 540s CE. They tell us a lot about the ancient Byzantine world, but they also suggest how archaeologists might someday unearth the story of the COVID-19 pandemic from the layers of stuff we’re dumping into landfills in 2020.

Gaza wine and Byzantine pilgrims

For thousands of years, people survived in Israel’s arid Negev Highlands by farming enough grain to feed their families and enough grapes to make their own wine. But under the Byzantine Empire (which arose in 330 CE as a successor to the Roman Empire), the Negev flourished. Cities sprang up in the desert, fueled by a new export trade: grapes for the famous Gaza wine, a sweet white wine that ancient chroniclers raved about and which was in demand from Britain to Yemen.

Gaza wine tied the remote Negev into the international Mediterranean economy, and it turned scattered small subsistence farms into larger commercial enterprises supplied by irrigation systems and pigeon-poop fertilizer. For a couple of centuries, the Byzantine Empire’s citizens paid well for a steady flow of Gaza wine, and the Empire built monasteries and sent religious pilgrimages to the Levant.

In 11 trash mounds from the ancient cities of Elusa, Shivta, and Nessana, Bar-Ilan University archaeologist Daniel Fuks and his colleagues found more than 10,000 grape, wheat, and barley seeds, which they radiocarbon dated to track the growth of commercial wine production—and its collapse in the wake of the plague.

Grapes have always been a staple around the Mediterranean, along with grains and olives. But in the 300s CE, grapes started accounting for a larger portion of the seeds getting discarded in trash heaps. By the mid-500s CE, grape seeds accounted for a quarter to nearly half of the seeds in trash heaps; that suggests that farmers who once grew a mix of grain and grapes to feed their families had started expanding their vineyards to produce more grapes for wine export.

Shards and spills

Broken pieces of pottery mixed in with those layers of the trash mounds tell the same story. Gaza wine made its way from the wineries to the port at Gaza on camelback, and then around the rest of the Mediterranean world (and beyond) in the holds of ships. The jars that carried the sweet white wine were distinctive: tall, narrow, with tapered bottoms that made them easier to lash onto the back of a camel or stack in a ship’s hold. As grape seeds became more common in Negev trash heaps, so did broken fragments of Gaza wine jars.

“This industry grew from practically nothing in the third century CE to appreciable production by the 5th century,” wrote Fuks and his colleagues.

And then, the bottom fell out of the Gaza wine trade. The cities of the Negev were mostly abandoned, and within a couple of centuries, most people were back to small settlements and subsistence farming. Grape seeds accounted for only 5 to 14 percent of the seeds in trash mounds.

The Plague of Justinian

According to radiocarbon dates of seeds and other organic material from the ancient trash heaps, the Negev wine industry’s crash coincided with the aftermath of the Plague of Justinian: the bubonic plague’s first-known visit to Europe, in 541 CE. The first wave of plague killed 20 percent of the population of Constantinople. Infection also devastated the trade port of Alexandria. Over the next 160 years, wave after wave of plague may have carried away up to half the population of the Byzantine Empire.

“Religious texts of the period suggest a heartfelt doomsday atmosphere,” wrote Fuks and his colleagues. Across the Byzantine Empire, many people were focused on survival.

Along with a smaller percentage of grape seeds, Fuks and his colleagues found fewer potsherds from Gaza wine jars in trash layers from the mid-500s CE. Combined, those things suggest a sudden drop-off in the Gaza wine trade. The trash-heap evidence lines up with other archaeological data from around the same time: people stopped building irrigation dams, shut down the dovecotes where pigeons pooped out fertilizer for the fields, and even gave up organized trash collection in the cities.

There’s no evidence that the plague travelled as far as the Negev Highlands, although historical sources describe outbreaks not too far away in southern Palestine. Instead, Fuks and his colleagues suggest that events hundreds of kilometers away actually killed the Negev grape industry. Raising cash crops for the international market had brought prosperity to the Negev, but it also left local farmers vulnerable to events in places like Constantinople and Alexandria.

Millennials didn’t kill this industry

Driven by economic forces, Negev farmers had pushed the land to the very limits of its carrying capacity with irrigation systems and fertilizer. When plague wiped out the market for Gaza wine, farmers couldn’t afford to maintain the irrigation dams and canals that made the whole high-input, high-output commercial farming system work. And intense focus on a single crop—grapes for making wine—made local farmers in the Negev even more vulnerable, because it was harder to adapt to changes in either the market or the weather.

Although the Plague of Justinian undoubtedly struck the final blow to the Negev grape industry, the story isn’t quite that simple. As we’ve seen in 2020, political tensions, climate change, and other events don’t stop even for a pandemic. And just like today, those events and their impacts influenced each other in complex ways.

“Indirect social factors—whether resulting from the plague and climate change or in addition to them—may have had significant economic repercussions for the viability of Negev viticulture,” wrote Fuks and his colleagues.

From all sides

Persia’s Sassanid Dynasty began harrying Justinian’s borders in 540, sacking Antioch and other Byzantine cities. Those incursions marked the start of 20 years of conflict—skirmishes with the Persians to the east and expensive wars with the Goths in Italy, where Justinian sought to retake Rome. The Byzantine historian Procopius writes that Justinian taxed agricultural products heavily to fund his wars of reconquest.

And climate probably also played a role. The plague came right on the heels of two volcanic eruptions in the late 530s CE, which blasted ash high into Earth’s atmosphere and triggered a decades-long cold snap called the Late Antique Little Ice Age. In Europe, the Late Antique Little Ice Age brought cooling and drought, but paleo-environmental evidence in the Negev suggests that the volcanic disruption brought more rain—which may have meant flash flooding that wreaked havoc on irrigation systems meant to store and control the flow of rainwater.

Meanwhile, if the Plague of Justinian did strike the Negev itself, the resulting labor shortages would have made it impossible to repair irrigation systems, scatter fertilizer on the fields, or harvest the grapes.

The archaeology of pandemics

With the Plague of Justinian in mind, it’s interesting to consider how future archaeologists might use today’s landfills to study the impacts of COVID-19. Archaeologists can study modern garbage heaps with the same methods they use to study ancient ones, and garbology (the archaeological study of trash) has been a busy field of study for decades. In layers dating from 2020, researchers might notice a sharp increase in food delivery containers, hand-sanitizer bottles, and disposable masks—but they might also notice trends and lines of evidence that we’re not even thinking about today.

And just like archaeologists studying how the Plague of Justinian impacted the ancient wine trade, archaeologists studying the early 21st century will probably conclude that our society was impacted not just by COVID-19 but by global climate change and a complex tangle of social and political events. Unlike the Byzantine grape farmers of the Negev, however, we still have the chance to shape what kind of story those future archaeologists will read in our landfills.

“The difference is that the Byzantines didn’t see it coming. We can actually prepare ourselves for the next outbreak or the imminent consequences of climate change,” said Fuks. “The question is, will we be wise enough to do so?”