An ancient bubonic plague outbreak often characterized as a
mass killer that felled Eurasian civilizations was actually pretty tame,
researchers say.

Known as the Justinianic plague, the outbreak likely
didn’t cause enough deaths to trigger major events
such as the eastern Roman
Empire’s decline, Islam’s rise and the emergence of modern Europe, say
environmental historian Lee Mordechai and his colleagues.

Many scholars have argued that the Justinianic plague caused
tens of millions of deaths starting in the sixth century and reduced European and
Middle Eastern populations by 25 to 60 percent. Economies crumbled as a result,
devastating what was left of the Roman Empire and ushering in a period of
cultural stagnation, from this perspective.

But several new lines of archaeological evidence related to
ancient population and economic changes challenge that scenario, Mordechai and
his team report December 2 in the Proceedings
of the National Academy of Sciences
.

“Support for the claim that the Justinianic plague was a
watershed event in the ancient world is just not there,” says study coauthor
Merle Eisenberg, an environmental historian at the University of Maryland’s
National Socio-Environmental Synthesis Center in Annapolis. Yet a scenario of
the plague outbreak wiping out populations and reshaping societies appears in
many textbooks on ancient history, he says.

The Justinianic outbreak, caused by the plague bacterium Yersinia pestis, occurred several
centuries before the more widely known Black
Death plague
, which killed tens of millions of people in the 14th century (SN: 1/17/16). An initial outbreak began
during the reign of Emperor Justinian, who ruled the eastern part of the Roman
Empire after the fall of Rome, and ran from around 541 to 544. Intermittent
plague reoccurrences lasted until around 750, and stretched around the
Mediterranean and into Europe and the Middle East.

Researchers in different disciplines have often wrongly assumed
that evidence from archaeology, genetics, ancient texts and other sources all
indicate that the Justinianic plague wreaked social havoc, contends geographer
Neil Roberts of the University of Plymouth in England. Mordechai’s team has
assessed evidence from across disciplines to reach a contrasting but plausible
conclusion, says Roberts, who did not participate in the study.

In one new finding that points to the Justinianic plague
having only a modest impact, land use and cereal cultivation remained largely
unchanged during the sixth century in several eastern Mediterranean regions
often said to have been shattered by plague. Based on ancient pollen data
collected by other investigators, Mordechai, also of the National
Socio-Environmental Synthesis Center, and his group found no signs of people
abandoning farmland in those areas, including agricultural sites near Roman
trade routes and cities such as Constantinople, now Istanbul, where plague
could have spread quickly.

Neither did burials of five or more deceased individuals in
the same grave increase in sixth century Europe, the researchers say. In
particular, they emphasize, evidence from 8,207 ancient graves across what’s
now England, Scotland and Wales suggests that multiple interments increased
slowly starting in the 300s, with no unusual jumps during the time of the
Justinianic plague. Mass burials represent another possible sign of a
particularly deadly plague outbreak, but in some regions could reflect a
cultural practice aimed at keeping deceased members of the same families or
social groups together.

Early historical texts and stone inscriptions from Europe and
the eastern Mediterranean contain few plague references, the investigators also
found. And other written sources indicate that official Roman legislation did
not decline after the 541 outbreak, as would be expected in a social crisis. Archaeological
finds from two Mediterranean sites suggest that coin circulation also remained
stable during the 540s. Roman texts point to similar stability at that time for
gold values.

What’s more, some researchers have assumed that the Justinianic
plague killed many Egyptians. But official papyruses dating to years from 520 to
570 don’t refer to a plague outbreak and contain no evidence of population
declines, land abandonment or drops in tax revenue, Mordechai’s team found.

Y. pestis DNA, now isolated from about 45 Europeans dating to around the time of the sixth century outbreak, doesn’t by itself mean that the plague killed huge numbers of people, the researchers contend. That’s because the Y. pestis associated with the Justinianic plague was not directly ancestral to later, especially deadly Y. pestis strains known to have caused the Black Death (SN: 10/14/11), the scientists say.

Although the Justinianic plague probably struck some densely
populated areas, “the idea that it was a blanket catastrophe affecting all
parts of the Mediterranean, Middle East and central and western European worlds
needs to be rethought,” says Princeton University’s John Haldon, a historian of
ancient Europe and the Mediterranean who did not contribute to the new
research.

Even the Black Death didn’t topple political systems, Haldon says. For instance, the Hundred Years’ War, waged between the kingdoms of England and France from 1337 to 1453, barely wavered as the Black Death spread. There’s no reason to expect that an apparently less deadly, sixth century plague capsized a big chunk of the Roman Empire or any other ancient state, he contends.