Many believed it was a judgement from God – millions dead as punishment for the sins of mankind.
In Britain alone, the Black Death wiped out up to half of the population when it struck between 1348 and 1350.
But now, new research has found that the plague may actually have been present in Western Asia a century before it devastated Europe.
A study in the journal Medical History suggests that the plague-causing bacteria Yersinia pestis was in the region in the 13th century.
Studies of chroniclers and physicians from the time shows evidence of outbreaks in places including Syria, Iraq and Egypt in the years following the Mongol conquest of Baghdad in 1258.
Mongol troops may have spread the infection, but the bacteria did not then have a way to travel beyond the immediate locales of outbreaks, meaning a pandemic did not occur.
Professor Nahyan Fancy from the University of Exeter and fellow researcher Dr Monica H. Green, an independent scholar, looked at more than a dozen pre-1348 chronicles, religious and medical texts from the region.
New research has found that the plague may actually have caused milder outbreaks in the Middle East a century before it devastated Europe. Above: A depiction of plague victims being buried during the Black Death, which struck between 1348 and 1350
Studies of chroniclers and physicians from the time shows evidence of outbreaks in places including Syria, Iraq and Egypt in the years following the Mongol conquest of Baghdad in 1258. Above: Hulagu Khan, who commanded the army that conquered Baghdad
Their work builds on a previous study that showed how contemporary observers were suggesting the new presence of a plague-like disease in western Asia in the second half of the 13th century.
The new study demonstrates by closely examining the symptoms described that this was likely caused by Yersinia pestis.
Professor Fancy said: ‘In the thirteenth century, of course, there were no microscopes and no means to conceive of bacteria as the cause of disease.
‘Rather, contemporary observers believed that epidemics were caused by “miasms”, airborne effluvia that could arise from scenes of decay, like the sites of great battles.
‘Observers linked outbreaks of plague in Syria, Iraq and Egypt up through 1260 to the Mongol conquest of Baghdad in 1258, where epidemic disease was reported even among the Mongol troops.’
She added: ‘This is what we are calling the “prodrome” of the pandemic, in which the bacterium is present in the region but a full-blown pandemic has not started raging yet.’
Dr Green explained: ‘We know now that the strains of Yersinia pestis that reached Europe in the fourteenth century are most closely related to those still found in Central Asian marmots.
‘That core biological narrative prompts us to look for an importation mechanism. The troops’ grain supplies in the 1250s could explain that. But what happened next?
‘Because humans in the Middle Ages had no concept of microbes, we will never find bacteria mentioned in our written sources.
‘But when a scribe reports “pestilence” and an infestation of fleas in his region more than 25 years before the Black Death, we need to pay attention.’
Non-white inhabitants of London died in greater numbers because of the ‘devastating effects’ of ‘premodern structural racism’, according to the research from the Museum of London
The Black Death is believed to have claimed its first victim in Britain in the summer of 1348. It spread slowly at first but then struck Exeter and later Bristol.
By December 1349, almost the entire British Isles were afflicted.
At the time, it was the worst natural disaster in European history.
It is estimated that in England alone the population of five to six million was reduced to around three million.
It was deemed by many to be a punishment from God for mankind’s wickedness.
Rich and poor suffered equally. King Edward III’s daughter Joan was one of the victims. The plague also claimed the life of the Archbishop of Canterbury.
In London, around 300 people died every day in the square mile. Each night, carts filled with piles of corpses made their way to the huge communal cemeteries outside the city walls.
William of Dene, a monk in Rochester, recorded: ‘The plague carried off so vast a multitude of people of both sexes that nobody could be found who would bear the corpses to the grave.
‘Parents carried their own children on their shoulders to the church and threw them in the common pit.
‘From these pits such an appalling stench was given off that scarcely anyone dared even walk beside the cemeteries.’
Overall, as many as 25million people in Europe were killed.
The Black Death subsided in Britain by the end of 1350, but there were further sporadic outbreaks until the late 17th century.
