Tigernán Ua Ruairc and a Twelfth-Century Royal Grant in the Book of Kells by Denis Casey explores one of the most significant surviving legal records contained within the Book of Kells. Published by Four Courts Press as part of the Maynooth Studies in Local History series, the book provides a detailed examination of a substantial land grant made by Tigernán Ua Ruairc, the powerful twelfth-century King of Bréifne (modern Counties Cavan and Leitrim).

Although Tigernán Ua Ruairc is often remembered for his association with the events leading to the Anglo-Norman invasion of Ireland, Casey shifts the focus to his achievements as a capable ruler who governed Bréifne for approximately fifty years. Using the surviving charter preserved in the Book of Kells, the study reveals how medieval Irish kings used land grants to strengthen political alliances, support the Church, and reinforce their authority.

The book examines:

• The history and significance of the land grant recorded in the Book of Kells
• Tigernán Ua Ruairc’s role as King of Bréifne
• The relationship between medieval Irish rulers and ecclesiastical institutions
• Land ownership, patronage, and legal traditions in twelfth-century Ireland
• The political and military landscape before the Anglo-Norman invasion
• The importance of Kells as both a religious centre and a repository of historical records

Casey combines close analysis of the medieval manuscript with archaeological, historical, and geographical evidence to reconstruct the grant and explain its wider significance. The study demonstrates that the Book of Kells was not only a masterpiece of illuminated art but also a valuable repository of legal and administrative records that illuminate the workings of Gaelic Ireland.

Written in an accessible style while maintaining academic rigour, the volume offers fresh insight into one of Ireland’s most influential medieval kings and the complex relationship between secular power and the Church during the twelfth century. It also highlights how surviving manuscript evidence can transform our understanding of Ireland’s medieval past.

Ideal for readers interested in medieval Irish history, the Book of Kells, Gaelic kingship, church history, manuscript studies, and early Irish politics, this concise study provides an authoritative introduction to a fascinating episode in Ireland’s medieval heritage.