One of his own: the Irish participant in the assassination of Tigernán Ua Ruairc
By Seán Ó Hoireabhárd
Riocht na Midhe, Volume 29, 2018
Introduction: “Tigernan Ua Ruairc, king of Breifni and Conmaicni, a man of great power for a long time, was killed by the same Saxons and by Domnall, son of Annadh [Ua Ruairc] of his own clan along with them …”
– Annals of Ulster 1172
As stated in the various collections of annals above, Tigernán Ua Ruairc was King of Bréifne and Conmaicne. In fact this kingdom reached its greatest extent during his long reign, between c. 1124 and his assassination in 1172. Ua Ruairc is most famous for his conflict with Diarmait Mac Murchada, the King of Leinster.
Mac Murchada either abducted or eloped with Ua Ruairc’s wife Derbforgaill in 1152, depending on the source consulted, and when Ua Ruairc helped engineer Mac Murchada’s fall in 1166, he also ensured Mac Murchada was driven overseas. In one of the best known episodes of Irish history, Mac Murchada then sought aid from the King of England Henry II, and returned with English barons and mercenaries. Ua Ruairc outlived Mac Murchada, who died in 1170.
Following a number of defeats attempting to oppose the English, Ua Ruairc submitted to the authority of Henry II in 1171. This submission was received by Henry II, but he subsequently made a grant of Meath, much of which was under Ua Ruairc’s control, to a lieutenant called Hugh de Lacy. This grant was awarded in 1172, and it was early in 1172 that a parley was arranged between Hugh de Lacy and Tigernán Ua Ruairc, where the latter was killed. Of interest to this brief study is the identity of an Irish dynast who was present at the parley in Hugh de Lacy’s entourage.