Archaeologists have uncovered a vertical shaft containing 123 bodies but how they died has so far remained a mystery.
The remains of men, women and children thought to be from the early 12th century were discovered in gardens a few metres from Leicester Cathedral.
It is one of the largest pit burials ever excavated in the UK, the Guardian reports.
Its not currently known why the bodies were placed in the shaft or what led to their deaths.
Their bones show no signs of violence – which leaves us with two alternative reasons for these deaths: starvation or pestilence, said Mathew Morris, project officer at Leicester University’s archaeological services. At the moment, the latter is our main working hypothesis.
Mathew said the excavations suggest the bodies were put into the shaft in three deposits in quick secessions.
It looks as if successive cartloads of bodies were brought to the shaft and then dropped into it, one load on top of another in a very short space of time, he said.
He and his team believe the people put in the shaft probably represented around 5% of the towns population at the time.
The burial pit is one of the biggest in the country (Picture: AP)He said other pit burials have previously been found in the region, but this is the biggest and the team have struggled to find any others in the country comparable.
Pestilences, fevers, hunger and famine are mentioned repeatedly in the Anglo-Saxon Chronicles from the the mid-10th century through to the mid 12th century, Mathew explained.
The burial fits within this timeframe and provides physical proof of what was happening across the country then, he added.
The team initially thought the people buried were victims of the Black Death, but radiocarbon testing on the bones showed they lived around 150 years before the disease hit English shores in 1348.
In the hope of discovering the real cause of death, samples from the bodies have been sent to geneticists at the Francis Crick Institute in London, where experts will search for viruses, bacteria or parasites.
Richard II is buried at Leicester Cathedral after his body was discovered under a nearby car park 12 years ago (Picture: PA)
King Richard IIIs skeleton, after it was uncovered under the car park (Picture: PA)The dig, which started in 2021 and is now complete, was part of an archaeological survey being carried out in the grounds of the cathedral after plans were approved to build a new heritage learning centre there.
Its hoped the centre will help Leicester Cathedral cope with a huge increase in visitors following the discovery of Richard IIIs body underneath a nearby car park 12 years ago and his subsequent reburial at the cathedral.
The archaeological team also discovered the remains of 1,237 men, women and children buried in the gardens from the early 11th century until the 19th century.
It’s a continuous sequence of 850 years of burials from a single population from a single place, and you don’t get that very often, said Mathew. It has generated an enormous amount of archaeology.
Other findings included Anglo-Saxon dwellings and a Roman shrine.
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