The Black Death claimed the lives of one-third of Europe's population in just five years.
The plague is fairly easy to suppress with antibiotics and pesticides.
A much less virulent version of the Black Death plague that killed a third of Europe's population in the 14th century is still present today, according to a study published Tuesday.
DNA testing on the skeletons of plague victims unearthed in a medieval London mass grave reveals part of the same gene sequence as the modern bubonic plague, despite its different attributes.
"At least this part of the genetic information has barely changed in the past 600 years" says Johannes Krause, one of the authors of the study, published in the Proceedings of the National Academy of Sciences (PNAS).
"Without a doubt, the plague pathogen known today as (yersinia) pestis was also the cause of the plague in the Middle Ages," he added.
The Black Death claimed the lives of one-third of Europe's population in just five years from 1348 to 1353, but modern outbreaks have been far less deadly, even given advances in medicine.