The O'Brien Clan

A Brief Outline of O'Brien History

From the tenth century, when the sept rose to the High Kingship of Ireland in the person of Brian Boru, down to the present day, the O'Briens have always been prominent in the history of the country.

Before Brian Boru's time, the Dalcassian clan, known as the Ui Toirdealbhaigh, to which they belonged, was not of outstanding importance in Thomond: the greatness of Brian gave them pre-eminence there and in due course the sept, which took the surname O'Brien from him, divided into several branches and possessed a great part of Munster, of which they were frequently kings.

The O'Briens of Ara (north Tipperary), a territory they acquired from the O'Donegans about the year 1300 had as chief Mac Ui Bhriain Ara; those of Co. Limerick gave their name to the barony of Pubbelebrien; another branch was located around Aherlow by the Galtees; and another south of the Comeragh Mountains on the rich lands near Dungarvan.
In all those areas, and especially in Co. Clare they are numerous to-day: the name, in fact, is so common that it comes sixth in the statistical list relating to Irish surnames, with an estimated population of more than thirty thousand persons. In this connexion it may be observed, that though fifty years ago one third of the people of the name was registered as plain Brien, nowadays it is rarely to be found without the prefix O.

The outstanding figure is, of course, Brian Boru (941 - 1014), whose remarkable career as High King of Ireland ended with his death on the field of the battle of Clontarf when the Norsemen were finally subdued. Brian, in fact used no surname; it was, however, in regular use forty years after his death.
According to Eleanor Hull's History of Ireland the first O'Brien to adopt the surname was Donagh Cairbre (1194-1242), son of Donal, who submitted to Henry II., From 1055 to 1616. The last year recorded by the Four Masters, O'Briens figure in the annals of every generation, over 300 individuals of the name finding a place in that great work.
In this respect they are outnumbered only by the O'Connors, and O'Neills and the O'Donnells.

In the "Annals of Innisfallen", which deal principally with the southern half of Ireland, the O'Briens appear more often than any other sept, though in this the MacCarthys run them close. Murrough O'Brien (d. 1551) was the first Earl of Thomond; Murrough of the Burnings (d. 1674) was sixth Baron Inchiquin.

Coming to modern times, the difficulty is to select a few names from the many O'Briens who have been prominent in the political and cultural history of the country. The descendants of Brian Boru, in the main line, have been peers of the realm under three titles, Earls and Marquises of Thomond, Barons and Earls of Inchiquin and Viscounts Clare. The two former have more often than not been on the side of England, notably Murrough O'Brien, first Earl of Thomond (d. 1551), who was one of the great Gaelic chiefs to acknowledge Henry VIII, and the other notorious Murrough O'Brien, sixth Baron Inchiquin (1614-1674) whose exploits during the war of 1641-1650 earned him the sobriquet "Murrough of the Burnings", not the least for his destruction by fire of Cashel.

The Viscounts Clare, on the other hand, present a different picture; the first of these, Daniel O'Brien (1577-1663), was a member of the Supreme Council of the Catholic Confederates; it was the third Viscount, also Daniel O'Brien (d.1690), who raised the famous Irish Brigade regiment known as Clare's Dragoons, which was later commanded in many famous battles on the continent by the fifth Viscount, Charle's O'Brien, whose distinguished military career ended when he was killed at the battle of Ramillies in 1706, while his son, Charles O'Brien, sixth Viscount (1699-1771), upheld the family tradition at Dettingen and Fontenoy, and became a Marshal of France.

Younger branches of these noble families produced William Smith O'Brien (1803-1864), born in Dromoland Castle, who broke away from the "landlord" tradition of his relatives and became one of the best known of the Young Irelanders. His daughter, Charlotte Grace O'Brien (1845-1909), was a philanthropist, author and zealous Gaelic Leaguer, and his brother, Edward O'Brien (1808-1840), devoted his short life to similar causes.

Other O'Briens whose names are honoured for their part in the struggle for the restoration of Irish independence are Most Rev. Terence Albert O'Brien (1600-1651). Dominican Bishop of Emly, who was hanged by Ireton after the Siege of Limerick; James Xavier O'Brien(1828-1905), the Fenian, and William O'Brien (1852-1928), who devised the "Plan of Campaign" and founded the United Irish League. Another William O'Brien (b. 1881), nationalist, labour leader and friend of James Connolly, was active in Irish affairs.

Add to all these Fitzjames O'Brien (1828-1862), the Irish author who was killed fighting in the American Civil War; Jermiah O'Brien (1740-1818), with his brothers John and William, heros of naval exploits against the British in the American War of Independence; Most Rev. John O'Brien (d.1767) and Rev. Paul O'Brien (1763-1820) two noted Gaelic scholars; and there are still many names which may justly be considered worthy of a place in this brief account of a great and famous Irish sept.