Archaeologists have uncovered a mass grave at a medieval site in Co Roscommon which they believe will be the first confirmed Black Death burial ground in this country.
DNA tests are to be carried out on the teeth of the 45 skeletal remains found at Kilteasheen, Knockvicar, to establish if the black plague bacteria is present.
The Black Death killed over 25 million people in Europe between 1347 and 1350. There is a reference in the Annals of Lough Key to the plague having reached the Roscommon area in the 1350s.
The archaeological team, under the leadership of Dr Chris Read, a lecturer in archeology at Sligo Institute of Technology, has established that the burial site - it is on top of two other layers of bodies - dates from the early to the mid-14th century.
"There have been other cases in this country where there was similar circumstantial evidence indicating that burial grounds were linked to the plague but nobody has used DNA to confirm it beyond doubt before," said Dr Read.
He said the bodies would be taken to a laboratory at the Sligo college, where staff would carry out the DNA tests on teeth.
"Because the plague killed people so quickly one would not find any evidence in the bone," said Dr Read.
During the five-week dig at Kilteasheen, the team, which includes 30 archaeology students from Sligo and the US, believed it identified a bishop's palace dating back to the 13th century, one of only two in the country.
The dig concludes today, and is part of a five-year project at the site overlooking Lough Key and the Boyle river.
It is a joint project by the archaeology departments of Sligo Institute of Technology and Webster University in St Louis, US. The American team is led by archaeologist Thomas Finan who did his PhD on medieval churches in the diocese of Elphin.
Mr Finan first visited the area to examine the remains of a building known locally as the Bishop's Seat.
This was thought to have been a church, but the team now believes it was a palace built in 1253 by Bishop Thomas O'Conor.
The Annals of Lough Key record that it was destroyed deliberately in 1259 by Hugh O'Conor to prevent it falling into the hands of the Anglo-Normans.
Of the remains thought to have been victims of the Black Death, Dr Read said: "The bodies included babies, children, adolescents, everyone."
He said the team had not established the age of two small, lower layers of bodies which could be anything from 50 to 200 years older that those believed to have died from the plague.
The bodies at the lower level were buried in individual graves while the upper bodies were buried in a mass grave.
The site is located on the property of farmers John and Tina Burke, of Riversdale House. Dig funding was provided by the Royal Irish Academy and the Heritage Council.
"We hope that after the tests are completed that the remains can be returned to the site but that will be a matter for the National Museum and the landowners," said Dr Read.
The Black Death was one of the worst killers in Europe's history, killing over 25 million people or a third of the continent's population between 1347 and 1350.
The plague was caused by a bacterium called yersinia pestis, which was carried by fleas on the black rat.
It came in three forms; bubonic, pneumonic and septicaemic. The bubonic plague was Europe's most common killer.
Ireland fell victim in the summer of 1348 when the plague broke out in Dublin and Drogheda.
One third or more of the population of cities died. Housing conditions and poor sanitation contributed to the disease's rapid transmission.
Many died of boils and abscesses which erupted on the legs and in the armpits.
The name Black Death comes from one of the symptoms, acral necrosis, which caused the skin to become black and purple.
