Two Different King Brians Almost United Ireland Into a Single Kingdom

(Brian Boru addressing his Army before the Battle of Clotarf 1014 AD, by James Ward (1851-1924), [Public Domain] via Creative Commons)

Throughout its long, tumultuous history, Ireland has never truly been unified. Whether the people in Ireland were warring amongst themselves or against invaders, or arguing about religion, they always seemed to be divided by something, if not by national borders, then by irreconcilable beliefs.
In medieval Ireland, however, two kings came close to unifying the people of their island—Brian Boru (c. 941-1014) and Brian O’Neill (r. 1241-1260).

In 10th century Ireland, a second wave of Vikings were beginning to raid and settle Irish lands. Brian Boru, located in western Ireland, took advantage of the chaos, and began to conquer his neighbors, Vikings and native Irish, alike. By 980, Brian Boru had conquered Limerick and Munster; next, Tara and Dublin fell to him in 999. As Brian Boru continued to conquer small Irish kingdoms, he proclaimed himself high king of Ireland. He expanded into Ulster and Leinster, but died in the 1014 Battle of Clontarf, throwing his kingdom into disarray.

The other king, Brian O’Neill, lived less than a century after the Norman kings of England began spreading their influence into Ireland. In his time, England was preoccupied with matters away from Ireland, so Brian O’Neill benefited from a resurgence of native Irish influence. In 1258, Brian O’Neill was proclaimed high king of Ireland by a coalition of minor kings. Though some Irish kings withheld their support from O’Neill, the high king was able to raise an army to fight the English. The military campaign, however, did not go well—Brian O’Neill was slain in the Battle of Downpatrick in 1260.

Written by C. Keith Hansley.



  • Ireland: A Short History (Third Edition) by Joseph Coohill. London: Oneworld Publications, 2008.

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