Person

Muirchertach Ua Briain

c. 1050–1119 · 11th century · Also known as Muirchertach O'Brien

Muirchertach Ua Briain was king of Munster and high king of Ireland with opposition, a great-grandson of Brian Boru. Ruling from 1086, he made Limerick a royal centre, gave the Rock of Cashel to the Church in 1101 and sponsored the reforming Synod of Cashel. His long rivalry with Domnall Mac Lochlainn of Ailech dominated Irish politics until illness broke his power after 1114.

Muirchertach Ua Briain
Image: Unknown author · Public domain · Wikimedia Commons

Mentioned in 2 state histories

Kingdom of MunsterKingdom of Ailech

See also

Cite this entry
APA
The Epoch Institute. (2026). Muirchertach Ua Briain. In The Epoch Institute Encyclopedia. https://the-epoch-institute.org/encyclopedia/muirchertach-ua-briain
MLA
“Muirchertach Ua Briain.” The Epoch Institute Encyclopedia, The Epoch Institute, 2026, https://the-epoch-institute.org/encyclopedia/muirchertach-ua-briain. Accessed .
Chicago
The Epoch Institute. “Muirchertach Ua Briain.” The Epoch Institute Encyclopedia. 2026. https://the-epoch-institute.org/encyclopedia/muirchertach-ua-briain.
Harvard
The Epoch Institute (2026) ‘Muirchertach Ua Briain’, The Epoch Institute Encyclopedia. Available at: https://the-epoch-institute.org/encyclopedia/muirchertach-ua-briain (Accessed: ).

Last reviewed October 2026Random entry ↻