kingdom · British Isles

Kingdom of Breifne

700 CE – 1256 CE (approx.)

A Gaelic kingdom of the drumlin country of Leitrim and Cavan, ruled by the O'Rourkes, whose king Tigernan Ua Ruairc helped bring about the Norman invasion of 1169.

Origins

Breifne emerged in the 8th century among the Ui Briuin of Connacht, whose branch, the Ui Briuin Breifne, settled the lakes and hills of later Leitrim and Cavan. The O'Rourke family became its leading dynasty by the 10th century.

Rule and society

Breifne was an upland kingdom of cattle, lakes and crannog dwellings. Its kings occasionally claimed the kingship of Connacht. Tigernan Ua Ruairc, ruler from about 1124 to 1172, fought Diarmait Mac Murchada of Leinster, who had abducted his wife Derbforgaill; their feud helped bring the Normans to Ireland. Tigernan was killed at Tlachtga in 1172.

Decline and legacy

After the death of its king in 1256, Breifne split between the O'Rourkes of West Breifne and the O'Reillys of East Breifne. Both survived until the late 16th and early 17th centuries.

Lineage

Kingdom of BreifneWest Breifne 1256 CE – 1605 CEEast Breifne 1256 CE – 1607 CE

Connections (1)

More states of British Isles →

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

Last reviewed October 2026Random state ↻