'Wikipedia' of the Middle Ages goes on display at Trinity

RTÉ News​

21-05-2025

One of the most important surviving medieval manuscripts written in Irish goes on public display after a two-year long project to conserve it.
The Book of Leinster, which was written in the 12th century in Old and Middle Irish is regarded as major source of Irish literature and history from the medieval period.
It will be available to view until mid-August as part of a new exhibition that forms part of the Book of Kells Experience at Trinity College, Dublin.
Having survived the for almost a millennium, in recent years the Book of Leinster was beginning to show its age, so the university embarked on a conservation project which took two years to complete.
The 400-page manuscript on vellum, which came to Trinity in 1786 in an unbound state, was unable to be put on display to the public or researchers for some time due to its fragile condition.
Dr John Gillis, Chief Manuscript Conservator at the Library in Trinity College Dublin carried out the conservation work by himself with a intricate and innovative toolkit that he has acquired and developed over decades of doing this specialised work.
"A single folio from the initial examination stage through to the cleaning and then, if there's distortion, removing distortion from the vellum, to the repair, to the physical damage, could take three or four days," said Dr Gillis.
"There's so much in it. It's like the Wikipedia of today."
He said the meticulous conservation work also involved replacing part of the manuscript with new vellum and reinforcing weakened areas with a form of thin collagen.
All of the work needs to be reversible to allow for any future changes in technology to restore the document but its improved condition now means it can once again be displayed and handled.
'Important source of Irish historical information'
Caoimhe Ní Ghormáin, Curator of Manuscripts and Archives at the Library in Trinity College Dublin says the Book of Leinster is one of the most important surviving scripts written in Irish and the stories and it contains tell us about life in the time of the many scribes behind it, who penned it over a fifty-year period.
"It's a very important source of Irish historical information and mythological information," she said.
"It contains some really important texts, such as one of the most complete copies of the Táin Bó Cúailnge, or the Cattle Raid of Cooley, which is the story of the warrior Cú Chulainn.
"There's also lots of genealogical lists, myths and sagas, poetry. It's really a compendium of information. There's so much in it. It's like the Wikipedia of today. It's a real snapshot into the Middle Ages."
It was by the man known as the prime historian of Leinster, Áed Úa Crimthainn, abbot of Tír-Dhá-Glas (Terryglass) monastery in Co Tipperary.
It was formerly known as the Lebor na Nuachongbála or Book of Nuachongbáil, a monastic site known today as Oughaval in Co Laois where the document was discovered before it was brought to Trinity College in the 18th century.
Other significant Irish language medieval manuscripts including the Yellow Book of Lecan and texts of Brehon law will go on display alongside the Book of Leinster in the exhibition which runs until 12 August.