Daniel or Donal[5][6] was born about 1577, the third and youngest son of Connor O'Brien and his second wife, Una O'Brien.[7] or in 1666 and was succeeded by his eldest surviving son, Connor.[8][9] His father was the 3rd Earl of Thomond.
His mother was a daughter of Turlough Mac-i-Brien-Ara. His parents were from different branches of the O'Briens, an important Gaelic Irish dynasty that descended from Brian Boru, medieval high king of Ireland.[10] His father was from the branch of the Earls of Thomond. His mother was from the branch of the O'Briens of Ara in County Tipperary. She was a sister of Murtogh O'Brien-Arra, Anglican bishop of Killaloe.
Whereas Donough, the eldest brother and heir apparent to the earldom of Thomond, was educated as a Protestant in England, the younger brothers Teige and Daniel were educated as Catholics. The father died in 1581 and was succeeded by Daniel's eldest brother as the 4th Earl of Thomond. His mother died in 1589 at Clare Castle.[11]
O'Brien was a member of the Supreme Council of the Catholic Confederates. In 1649 he fought the Cromwellians in Clare. He surrendered Clare Castle on 5 November and Carrigaholt Castle on 9 November.
In June 1652, at Ross Castle near Killarney, O'Brien together with Lord Muskerry surrendered to Ludlow. O'Brien served as a hostage to guarantee Muskerry's compliance with the terms.[25][26]
Restoration, Viscount Clare, and death
At the Restoration O'Brien returned to Ireeland. On 11 July 1662 Charles II created him Baron Moyarta and Viscount Clare.[27] The honour was intended for his grandson Daniel,[28] into whose hands the estate was directly conveyed.[29] Lord Clare, as he now was, attended the House of Lords during the Irish Parliament 1661–1666. He died in 1663[7] or in 1666 and was succeeded by his eldest surviving son, Connor.[8]
^This family tree is based on a pedigree of the viscounts Clare,[1] as well as genealogies of the viscounts of Clare[2] and the Earls of Thomond.[3][4] Also see the lists of siblings and children in the text.
^Burke 1883, p. 206, left column. "III. Catherine m. 1st Maurice, Lord Roch, who d.s.p.; and 2ndly Sir Donal O'Brien, of Carrigichouly, brother of Donogh Earl of Thomond, and ancestor to the Viscount Clare ..."
^O'Hart 1892, p. [archive.org/details/irishpedigrees00unkngoog/page/167/ 167, left column, line 4]. "124. Sir Donal, son of Connor; Lord of Moyarta and Carrignoulta (now Carrigaholt) ..."
^ abOhlmeyer 2004, p. 358. "O'Brien, Daniel, first viscount Clare (1577?–1663)"
^ abcÓ Siochrú 2009, 3rd paragraph, 3rd sentence. "He died in 1666 and was succeeded by his eldest surviving son Conor, and then in 1670 by Daniel, his grandson."
^Cokayne 1913, p. 251, line 29. "Daniel O'Brien, of Moyarta and of Carrigaholt, co. Clare, 3rd and ygst s. [youngest son] of Connor (O'Brien), 2nd Earl of Thomond [I. [Ireland] ], by his 2nd wife, Ownye, da. [daughter] of Turlogh Mac-i-Brien-Ara ..."
^Cokayne 1896, p. 391, Note b. "They were descended from the celebrated Brien Boroihme, principal king of Ireland (1002–1004) through his grandson Turlogh ..."
^ abCunningham 2009, last paragraph, last sentence. "Úna, who died at Clare castle, Co. Clare, in 1589."
^ abPollard 1895a, p. 310, right column, line 9. "Daniel was attacked in the castle of Ibrickan on which a treacherous assault was made on 1 Feb. 1599. The castle surrendered and O'Brien was wounded and made prisoner;"
^Pollard 1895b, p. 313, left column, line 46. "In 1599 O'Donnell invaded Clare, ravaging the country, capturing most of the castles, and making a prisoner of Thomond's youngest brother, Daniel O'Brien, afterwards first Viscount Clare, who had been left to defend it."
^Ó Siochrú 2009, 1st paragraph, 4th sentence. "O'Brien married Catherine, widow of Maurice, Viscount Roche of Fermoy, and third daughter of Gerald Fitzgerald ..."
^ abLodge 1789, p. 33. "... Donough [O'Brien], his heir who married Elizabeth, daughter of Sir Thomas Southwell, of Polylong in the county of Cork, Knt. widow of Sir John Dowdall of Kilfinny, and dying at Limerick 6 August 1638, was buried in St Mary's church in the tomb of his ancestors;"
^Harris 1930, p. 1193, left column, line . "k. [knight] of the shire, in England, one of the representatives of a shire or county in Parliament, in distinction from the representatives of cities and boroughs."
^ abHouse of Commons 1878, p. 608, row 17. "1634 / - Nov. / Sir Daniel O'Bryen (knt.) vice Brien absent in England / Carigencoltie / ditto [Clare County]"
^ abÓ Siochrú 2009, End of 2nd paragraph. "... he submitted to the English parliament under the articles agreed the following year by Donogh MacCarthy, Viscount Muskerry. O'Brien was one of the hostages ..."
^Firth 1894, p. 322, line 4. "... his son together with Daniel Obryan were delivered to me [Edmund Ludlow] as hostages ..."
^ abCokayne 1913, p. 252, line 1. "At the age of 80 or upwards he was cr. [created] 11 July 1662, Baron Morarta and Viscount Clare [or O'Brien of Clare], co Clare [I.[Ireland] ]."
^Cokayne 1913, p. 252. "[Daniel, his grandson] was in attendance on Charles II during his exile, and through his influence the peerage for his grandfather was obtained."
^O'Donoghue 1860, p. 323. "... set out and allotted onto Daniel O'Brien, Esq., son and heir to Conor ..."
^Hayes-McCoy 1976, p. 124. "The earl, O'Donnell, and Maguire attacked Bagenal on the march at the Yellow Ford, between Armagh and the Blackwater, on 14 August [1598], and defeated him ..."
^Warner 1768, p. 6. "... the twenty-third October [1641] ... seized all the towns, castles, and houses belonging to the Protestants which they had force enough to possess;"