Justinian Plague Crippled Byzantine Empire with Help of Pesky 'Black Death' Bacterium [Videos]

As Emperor Justinian's soldiers put their enemies to the sword in an aggressive campaign to recapture lost Roman territories, a devastating plague cut a swath through the Mediterranean population and claimed the lives of over 100 million people. The contagion ravaged the region between the sixth and seventh century, and preceded the infamous 'Black Death,' and 'Modern Plague' of the nineteenth and early twentieth century. Now, scientists at the Johannes Gutenberg University Mainz in Germany have pinpointed the root cause of the plague: a pesky bacterium known as Yersinia pestis.  

Years ago, study author Dr. Barbara Bramanti conclusively proved that Yersinia pestis was the culprit behind the 'Black Death,' otherwise known as the Bubonic Plague. With their recent discovery, Bramanti's team has found a common thread between two of humankind's three most catastrophic events. So, what is Yersina pestis?

The CDC explains that the bacterium "has been used as a weapon of biological warfare for centuries. Some warfare strategies have included catapulting corpses over city walls, dropping infected fleas from airplanes, and aerosolizing the bacteria during the Cold War."

The plague is typically transmitted through rodent flea bites, which most frequently causes septicemic, pneumonic, and bubonic illnesses. Symptoms of Bubonic plague include chills, swollen lymph nodes, headaches, and fever. Pneumonic plague targets the respiratory system and often results in bloody mucous, chest pain, and shortness of breath. Septicemic plague kills tissue on the extremities and incurs abdominal pain and bleeding.

"For a long time time scholars from different disciplines have intensively discussed about the actual etiological agents of the past pandemics," says Bramanti in a press release. "Only ancient DNA analyses carried out on skeletal remains of plague victims could finally conclude the debate."

However, the scientist adds, "It remains questionable whether at the time of the Byzantine Emperor Justinian only one strain or more were disseminated in Europe, as it was at the time of the Black Death."

The study was published in the journal PLOS Pathogens.