Where the Considine surname comes from, how the Considines descend from Brian Boru through a 12th-century bishop of Killaloe, and which DNA test confirms an O’Brien line.

The Considines (Mac Consaidín, “son of Consaidín”, the Irish form of Constantine) are a branch of the O’Briens of Thomond. Their ancestor was Consaidín Ua Briain, Bishop of Killaloe, who died in 1194 and was a great-great-great-grandson of Brian Boru. That makes the Considines one of the few surnames on this site that descend from Brian himself, not just from his wider kindred.

Considine at a glance

  • Irish form: Mac Consaidín
  • Meaning: son of Consaidín, the Irish form of Constantine
  • Ancestor: Consaidín Ua Briain, Bishop of Killaloe, died 1194
  • Kindred: O’Brien, direct descendants of Brian Boru
  • Found today: mainly Clare, especially around Ennis
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Origin of the name

Consaidín is a Gaelic borrowing of Constantine, a name that came into Ireland through the church. The family’s founder was Consaidín Ua Briain, son of Toirdhealbhach mac Diarmada Ua Briain, King of Thomond. The line runs back through the kings of Thomond to Tadc, Brian Boru’s son. Some writers instead derive the Considines from Domhnall Mór O’Brien, King of Munster, who also died in 1194. Both accounts put the family firmly inside the O’Brien dynasty.

The Considines of Thomond

Consaidín held the see of Killaloe, the cathedral town where Brian Boru had his royal centre at Kincora. Clare County Library counts the Considines among the learned families of Thomond, alongside the Clancys, who were brehons to the O’Briens, and the McGraths, their poets. The surname has stayed rooted in Clare ever since, and it is still most common around Ennis.

Considine DNA

A Considine man of the Thomond line should carry R-L226 (Irish Type III) and sit on the O’Brien branch of the Dalcassian tree. That is something few surname holders can test for directly. A Y-37 test from Family Tree DNA confirms the R-L226 pattern, and Big Y-700 can show how close your line sits to tested O’Briens. Women and anyone with a Considine grandmother should take Family Tree DNA’s Family Finder. Our Brian Boru descendants and DNA guide explains the O’Brien branches in detail.

Considine places to visit

Related surnames

See the MacMahons, the other O’Brien branch, and the O’Deas, whose Royal branch carries O’Brien DNA. For the heraldry of the line, see the O’Brien coat of arms explained, or browse all Brian Boru kindred surnames.

Frequently asked questions

Is Considine an Irish name?

Yes. Considine is the anglicised form of Mac Consaidín, a Clare family descended from the O’Briens. The personal name behind it is a Gaelic form of Constantine.

Are the Considines descended from Brian Boru?

Yes. Their ancestor, Consaidín Ua Briain, Bishop of Killaloe (died 1194), was a great-great-great-grandson of Brian Boru.

What does the name Considine mean?

It means “son of Consaidín”, the Irish form of Constantine, from the Latin constans, meaning steadfast.

Where is the Considine family from?

County Clare, the old kingdom of Thomond. The name is still most common around Ennis.

Sources

  1. Clare County Library, Learned Families of Thomond.
  2. C. Thomas Cairney, Clans and Families of Ireland and Scotland: the O’Briens and their branches (1989).