kingdom · British Isles

Kingdom of Thomond

1118 CE – 1543 CE · capital Limerick; later Clonroad (Ennis)

The O'Brien kingdom of North Munster, descendant of Brian Boru's power base, which kept its independence until 1543.

Origins

Thomond arose from the Dal Cais lands in Clare and Limerick. In 1118 the Treaty of Glanmire, imposed by Turlough O'Connor, split Munster, leaving the O'Briens with the north, Tuadmumu. Their capital was Limerick, the former Kingdom of Limerick.

Rule and society

The O'Brien kings were patrons of churches such as Holy Cross, Killaloe and Limerick's cathedral, founded by Domnall Mor O'Brien. After losing Limerick to the Normans in the 1190s, they ruled from Clonroad near Ennis. In 1318 Muirchertach O'Brien defeated the Normans at Dysert O'Dea, preserving Gaelic rule west of the Shannon.

Decline and legacy

In 1543 Murrough O'Brien surrendered his kingship to Henry VIII and became Earl of Thomond under the Kingdom of Ireland. His lands became County Clare in the 1570s.

Lineage

Kingdom of Munster 400 CE – 1118 CEKingdom of ThomondKingdom of Ireland 1542 CE – 1800 CE

Connections (1)

More states of British Isles →

Cite this page
APA
The Epoch Institute. (2026). Kingdom of Thomond. In The Epoch Institute States Register. https://the-epoch-institute.org/state/kingdom-of-thomond
MLA
“Kingdom of Thomond.” The Epoch Institute States Register, The Epoch Institute, 2026, https://the-epoch-institute.org/state/kingdom-of-thomond. Accessed .
Chicago
The Epoch Institute. “Kingdom of Thomond.” The Epoch Institute States Register. 2026. https://the-epoch-institute.org/state/kingdom-of-thomond.
Harvard
The Epoch Institute (2026) ‘Kingdom of Thomond’, The Epoch Institute States Register. Available at: https://the-epoch-institute.org/state/kingdom-of-thomond (Accessed: ).

Last reviewed October 2026Random state ↻