Scientists rebirth one of the most 'rampant killing' plagues of all time

German scientists have brought a plague, which killed half of the European population through medieval times, back from the dead.

Researchers have uncovered Yersinia pesti - a relatively harmless stomach bug that became a rampant killer - to figure out why some diseases die off and others flourish.

Y. pestis is a 1500-year-old bacteria that started centuries before the Black Death that swept through Europe in the Middle Ages.

It is believed to be the cause of the Justinian Plague and the Black Death - Bubonic Plague - which started in 541 AD and killed more than 25 million people over the next two centuries.

Researchers at the Max Planck Institute and the University of Tubingen in Germany have recovered corpses that contain the bacteria from sixth century skeletons found in Altenerding.

The bones were found in the ancient southern German burial site near Munich, and belonged to some of the first people who died from the plague.

Researchers Michal Feldman, Johannes Krause and Michaela Harbeck anaylsed teeth and skeletal remains of two ancient plague victims.

From this, they were able to extract the DNA to reconstruct the disease.

They then reconstructed the skeleton of the victim, which was excavated 50 years ago, and created the first high-coverage genome of the bacterial agent responsible for the plague.

“We were very fortunate to find another plague victim with very good DNA preservation in a graveyard just a few kilometers from where the individual analysed [by Wagner] was found,” Harbeck said in a statement.

“It provided us with the opportunity to reconstruct the first high-quality genome, in addition to the previously published draft genome.

The genome has revealed 30 newly identified mutations and structural rearrangements unique to the Justinianic strain., as well as correcting 19 false positive mutations.

The findings also suggested that the strain was more genetically diverse than previously thought.

"Our research confirms that the Justinianic plague reached far beyond the historically documented affected region and provides new insights into the evolutionary history of Yersinia pestis," Feldman said.

Although the reconstructions broadened scientists' understanding of pathogen evolution, researchers are yet to discover how the plague suddenly vanished.