Who Brian Boru was, how he rose from Killaloe to High King of Ireland, how he died at Clontarf in 1014, and where to see his Ireland today
Brian Boru, High King of Ireland (c. 941 to 1014)
Brian Boru was the most famous king in Irish history. Born around 941 into the Dál gCais, a minor ruling family near Killaloe in County Clare, he fought his way to the kingship of Munster in 978 and became High King of Ireland in 1002. He was killed at the Battle of Clontarf on Good Friday, 23 April 1014, in the hour of his army’s victory, and was buried at Armagh.
His descendants took his name, becoming the O’Briens, and ruled Thomond for five centuries. This site covers his life and the Ireland he left behind, from the places you can visit to the families who descend from him.
Brian Boru: quick facts
- Irish name: Brian Bóruma mac Cennétig
- Born: c. 941, Dál gCais territory around Killaloe, County Clare
- Father: Cennétig mac Lorcáin, King of Thomond
- King of Munster: from 978
- High King of Ireland: from 1002
- Royal seat: Kincora, Killaloe
- Title: “Imperator Scotorum”, emperor of the Irish, recorded in the Book of Armagh in 1005
- Died: 23 April 1014, Battle of Clontarf, aged about 73
- Buried: St Patrick’s Cathedral, Armagh
Why was he called Brian Boru?
Bóruma, anglicised as Boru, is usually read as “of the tributes”, referring to the cattle tribute he took from the kingdoms he conquered. It may also come from Béal Bóruma, the ringfort just north of Killaloe now known as Brian Boru’s Fort, which guarded the river crossing below his royal seat. Either way, the name was a nickname. To his contemporaries he was Brian mac Cennétig, Brian son of Cennétig.
Brian Boru’s life: a timeline
| Year | Event |
|---|---|
| c. 941 | Born into the Dál gCais, the ruling kindred of what is now east Clare. |
| 976 | His elder brother Mathgamain, King of Munster, is murdered by rivals. Brian takes over leadership of the Dál gCais. |
| 978 | Defeats and kills his brother’s killer, Máel Muad, at Belach Lechta and becomes King of Munster. |
| 997 | Meets the High King, Máel Sechnaill mac Domnaill, at Clonfert. The two agree to split Ireland between them, with Brian taking the south. |
| 999 | Defeats Leinster and the Norse of Dublin at Glenn Máma and takes Dublin. Its king, Sitric Silkbeard, submits and later marries Brian’s daughter. |
| 1002 | Máel Sechnaill submits to him. Brian becomes High King of Ireland. |
| 1005 | Visits Armagh, lays gold on the altar and is recorded in the Book of Armagh as “Imperator Scotorum”. |
| 1012 to 1013 | Leinster and Dublin rebel. Brian besieges Dublin without taking it. |
| 1014 | Wins the Battle of Clontarf but is killed in his tent, along with his son Murchad and grandson Toirdelbach. Buried at Armagh. |
The full story of his last campaign, and the myths that grew up around it, is in our guide to the Battle of Clontarf.
How Brian Boru changed Ireland
Before Brian, the high kingship of Ireland had been held for centuries by the Uí Néill dynasties of the north and midlands. Brian was the first outsider to take it by force, and he came from a family that had been minor players only two generations earlier. He showed that the title could be won rather than inherited. For the next 150 years, Ireland’s strongest kings, including his own great-grandson Muirchertach Ua Briain, fought to rule the whole island in the same way.
He also changed how Ireland remembered itself. A century after his death, his descendants commissioned Cogadh Gáedel re Gallaib, a history casting Brian as the saviour of Ireland from the Vikings. That version shaped the popular image of him for 900 years. Modern historians see a more complicated figure: a brilliant and ruthless politician who used Norse fleets and troops when it suited him. Our guide to the best books about Brian Boru covers the histories that separate the man from the legend.
Brian Boru’s family and descendants
Brian married several times. His wives included Gormflaith, sister of the King of Leinster and mother of Sitric Silkbeard of Dublin. His son Donnchad ruled Munster after him, and through his son Tadc came the line of O’Brien kings. The surname Ua Briain, “descendant of Brian”, became fixed within a few generations.
Today the O’Briens and the Clare MacMahons claim direct descent from him, and many more families, including the Kennedys, MacNamaras, O’Gradys and Hogans, share his Dál gCais kindred. Men of these families often carry a distinctive Y-DNA marker, R-L226. Read our guide to Brian Boru’s descendants and DNA, browse the surnames of his kindred, or see what lies behind the O’Brien coat of arms.
Test your paternal line with Y-DNA.
Explore Brian Boru’s Ireland
Are you his descendant?
What your surname and DNA can and can’t prove about descent from Brian Boru.
Visit Brian Boru’s Ireland
His fort at Killaloe, the Rock of Cashel, Clontarf and his grave at Armagh, with tours and a 4-day itinerary.
The Battle of Clontarf
What really happened on Good Friday 1014, and how Brian died.
The Brian Boru harp
Ireland’s national emblem, why it isn’t his, and how to see it at Trinity College.
Surnames of his kindred
MacNamara, Kennedy, O’Grady, Hogan, McGrath, MacMahon and Casey.
Cruise Lough Derg
Hire a cruiser and moor at Killaloe, Brian’s royal centre, by water.
Brian Boru’s March
The traditional tune, its real history and the best recordings.
Best books about Brian Boru
From Seán Duffy’s history to Lion of Ireland.
Brian Boru’s legacy today
- The O’Brien name: carried by hundreds of thousands of people worldwide, and one of the most common surnames in Ireland.
- The harp: the medieval Trinity College harp, long called the Brian Boru harp, is the model for Ireland’s state emblem. See it with a Book of Kells ticket.
- Killaloe: his home town still celebrates him every July with Féile Brian Ború, and the new Brian Boru Bridge across the Shannon opened there in 2025.
- Music: from the traditional Brian Boru’s March to the Brian Boru bagpipes, patented in 1908 and still played by pipe bands in Northern Ireland.
Frequently asked questions
Who was Brian Boru?
A king from County Clare who became King of Munster in 978 and High King of Ireland in 1002. He died at the Battle of Clontarf in 1014 and is the ancestor of the O’Brien family.
How did Brian Boru die?
He was killed in his tent at the Battle of Clontarf on 23 April 1014 by Brodir, a Norse commander fleeing the battlefield. Brian’s army won the battle.
Where is Brian Boru buried?
At St Patrick’s Church of Ireland Cathedral in Armagh, where a plaque on the north transept wall marks the spot.
Did Brian Boru drive the Vikings out of Ireland?
No. The Norse kingdom of Dublin survived Clontarf and remained a Hiberno-Norse town until the Anglo-Normans took it in 1170.
Was Brian Boru the last High King of Ireland?
No. Máel Sechnaill resumed the title after Brian’s death. Ruaidrí Ua Conchobair (Rory O’Connor), who reigned until the Anglo-Norman invasion, is usually called the last High King.
Where did Brian Boru live?
At Kincora in Killaloe, County Clare, overlooking the River Shannon. Nothing of the palace survives, but his ringfort, Béal Ború, can be visited just north of the town.
Sources
- Seán Duffy, Brian Boru and the Battle of Clontarf (Gill & Macmillan, 2013).
- Máire Ní Mhaonaigh, Brian Boru: Ireland’s Greatest King? (Tempus, 2007).
- Annals of Ulster and Annals of Inisfallen, entries for 976 to 1014 (CELT, University College Cork).
- Heritage Ireland (OPW), Brian Boru’s Fort.
- Visit Armagh, St Patrick’s Cathedral and Brian Boru.