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

Editor's note: On September 8, it was announced that Queen Elizabeth II had passed away, at her Scottish residence, Balmoral. She was the longest-serving monarch in British history, having served for 70 years. The Queen was 96 years old.

Turns out Queen Elizabeth was of royal lineage not only in Britain but also in Ireland. 

The monarch was a descendant 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 her mother, Elizabeth Bowes Lyon, who is a descendant of the Irish-born Duke of Wellington. 

Her son, King Charles, has two links to Brian Boru. Ahead of the now King's recent visit to Kilkenny, 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 Sept 2022.