Dictionary of National Biography, 1885-1900/O'Brien, Barnabas
O'BRIEN, BARNABAS, sixth Earl of Thomond (d. 1657), was the second son of Donough O'Brien, fourth earl of Thomond [q. v.], by his second wife, Elizabeth, fourth daughter of Gerald Fitzgerald, eleventh earl of Kildare [q. v.] His elder brother, Henry, fifth earl of Thomond, who succeeded to the earldom on his father's death in 1624, was a strenuous adherent of the government in Ireland, was warmly commended by Strafford for his loyalty, and died without male issue in 1639. Barnabas entered the Irish parliament in 1613 as member for Coleraine. In 1634 he was returned for Clare as colleague of his uncle, Daniel O'Brien, afterwards first Viscount Clare [q. v.]; but, being compelled to go to England for a time, a writ was issued for a fresh election. In 1639 he succeeded his brother as sixth earl, and applied for the governorship of Clare, which Strafford refused him on the ground that his conduct differed entirely from that of his brother, and that he deserved nothing. Nevertheless he was lord-lieutenant of Clare in 1640-1. When the Irish rebellion broke out he attempted to maintain neutrality, in spite of the support given by his kinsmen to the confederation (Carte, Ormonde, ii. 146), and did not sign the oath of association in 1641. He lived quietly on his lands in Clare, and was in frequent communication with Ormonde. In 1644 the council of the confederation forbade Thomond's agents to collect his rents, and even formed a scheme for seizing his chief stronghold at Bunratty, which his uncle, Sir Daniel O'Brien, was appointed to carry out. Thereupon Thomond, finding that no troops were forthcoming wherewith to defend Bunratty Castle, entered into negotiations with the parliamentarians, in spite of Glamorgan's remonstrances. At the instigation of his kinsman, Morough O'Brien, first earl of Inchiquin [q. v.], he admitted a parliamentary garrison to the castle, and went to live in England (Bloody News from Ireland, 1646, pp. 4-5; Lodge, Desid. Cur. Hib. ii. 193-4, 322).
Thomond soon joined the king at Oxford, and received, on 3 May 1645, a patent creating him Marquis of Billing in Northamptonshire (Baker, Northamptonshire, i. 20-1). But the patent never passed under the great seal. A few years later he petitioned parliament for the recovery of 2,000l. which had been seized in Bunratty, pleading that his real estate was in the hands of the Irish rebels, and that he had spent 16,000l. on the parliamentary cause. His petition was granted, and he apparently gave no cause for suspicion to the Commonwealth or protectorate, for his son's request, on 15 Dec. 1657, for the governorship of Thomond was favourably received by Henry Cromwell (Thurloe, vi. 681). He died in November 1657, and his will, dated 1 July 1657, in which he left some bequests to Great Billing, was proved in England on 6 Feb., and in Ireland on 28 April in the same year. Lodge (ed. Archdall, ii. 37) maintains that Thomond was of strict loyalty, religion, and honour, and that his lands were taken from him during the rebellion through the unnatural conduct of his nearest relations; it was also believed that he gave up Bunratty at Ormonde's instigation (Gilbert, Contemp. Hist, of Affairs in Ireland, i. 105-6).
Thomond married Mary, youngest daughter of Sir George Fermor and widow of James, lord Sanquhar, by whom he had one son, Henry, his successor (1621-1691), who matriculated from Exeter College, Oxford, on 19 Aug. 1636, aged 15, became governor of Clare, and died at Billing on 2 May 1691; and one daughter, Penelope, married to Henry Mordaunt, second earl of Peterborough [q. v.][Authorities quoted; Lodge's Peerage, ed. Archdall, ii. 37, &c.; Collins's Peerage of England, passim; Cal. State Papers, Dom. Ser. 1645-7, pp. 243, 429; Cal. Proc. of Committee for Advance of Money, pp. 634, 947; Morrin's Close and Patent Rolls, Ireland, iii. 41; Clarendon State Papers, ed. Macray, iii. 381; Gilbert's Contemporary History of Affairs in Ireland and Hist, of the Confederation, passim (in the index to the latter he is confused with his brother Henry, fifth earl); Carte's Ormonde, passim; Ludlow's Memoirs, ed. Firth, i. 18; Cox's Hibernia Anglicana, passim; Whitelocke's Memorials, pp. 201, 420; Commons' Journals, vi. 279, 445; Official Returns of Members of Parl.; Dwyer's Diocese of Killaloe, pp. 196, 206, 220, 267; O'Donoghue's Hist. Memoirsof theO'Briens, passim; Carlyle's Oliver Cromwell, ii. 147; Meehan's Confederation of Kilkenny; Strafford Papers, ii. 98, 113, &c.; Narratives illustrative of the Contests in Ireland (Camd. Soc.), passim; Rinuccini's Embassy in Ireland, transl. Hughes, pp. 150, 155, 159; C. G. Walpole's Kingdom of Ireland, p. 241; Castlehaven's Memoirs, ed. 1753, p. 74.]