Queen Elizabeth and King Charles III are descended from the Irish High King Brian Boru, who ruled Ireland from 1002 to 1014, facing his downfall in the Battle of Clontarf. 

It may come as a shock to many but Queen Elizabeth II and King Charles III are descended from the Irish High King Brian Boru, who ruled Ireland from 1002 to 1014, facing his downfall in the Battle of Clontarf. 

The monarchs are descendants of Brian Boru, the fearsome High King of Ireland who met his downfall in the Battle of Clontarf in 1014. 

This lineage is traced through Queen Elizabeth II's mother, Elizabeth Bowes Lyon, who is a descendant of the Irish-born Duke of Wellington. 

Her son, King Charles III, has two links to Brian Boru. Ahead of the now King's visit to Kilkenny in 2017, local archivist John Kirwan wrote to His Royal Highness’ London home, Clarence House, informing him that he had at least three lines of Irish ancestry.  

“Two,” he wrote, “date back from Brian Boru. One is from Brian Boru's son Teige while the other is from Boru's granddaughter Dearbforgail, which descends down through the McMorrough Kavanaghs, kings of Leinster, including Dermot McMorrough Kavanagh who enlisted the help of the Normans to regain his Leinster throne c. 1169-71.”

But before you start getting notions, consider this tidbit from DCU lecturer Dr. Mark Humphreys: "Brian Boru is the ancestor of every English monarch from 1399 to the present. Almost certainly, more people in England can prove descent from Brian Boru than people in Ireland."

Yes, it's true. Even the Duchess of Cambridge Kate Middleton, a member of the royal family by marriage, is yet another member of the royal family descended from Brian Boru, and she also has genealogical links to the Irish singer Chris de Burgh. 

* Originally published in 2018, updated in May 2023.