Brian Ua Néill

Brian Ua Néill
High King of Ireland
PredecessorRuaidrí Ua Conchobair (1166–1198)
Successornone (Edward Bruce claimant 1315–18)
King of Tír Eoghain and King of Ailech
PredecessorDomhnall Óg mac Aodha Méith Ó Néill
SuccessorAodh Buidhe mac Domhnaill Óg
Died14 May 1260 near Downpatrick, Ireland
IssueDomhnall mac Brian Ó Néill
DynastyNorthern Uí Néill (Cenél nEógain)
FatherNéill Ruaidh Ó Néill

Brian mac Néill Ruaidh Ó Néill (died 14 May 1260), also known as Brian O'Neill, was the High King of Ireland from 1258 to 1260. His status as High King is disputed by some, as the forces of the O'Briens of Thomond failed to support him in the Battle of Druim Dearg in 1260, which contributed to him being killed. However, they had both submitted by treaty to him and given hostages to him prior to that.

Revolt in Ireland

Due to the increasing pressure of the Norman colonists, under the Lordship of Ireland, revolts began to flare across Ireland. Tadhg O'Brien, son of the King of Thomond defeated the colonists in 1257 and plundered their lands. Hugh de Lacy's death in 1243 meant that the Earldom of Ulster was still in a period of lax administration.

In 1255, Brian (who at this time was King of Tir Eoghain) seized this opportunity to raid the colonists' lands across the River Bann into Ulaid and destroy any towns and castles that he encountered. Meanwhile, Aodh O'Connor, the son of the King of Connacht, expanded his territory by conquering the neighbouring Kingdom of Breifne in 1256 (with backing from Brian).[1]