1111 in Ireland

Incumbents

• High King of Ireland: Domnall [Ua Lochlainn]

Events

• Synod of Rathbreasail, presided over by Cellach Ua Sinaig, Abbot of Armagh is held. Ireland is divided into territorial dioceses under two metropolitans, the Archbishop of Armagh and the Archbishop of Cashel.
• Domnall mac Taidc temporarily seizes the Kingdom of the Isles by force.