became in 1551 second Earl of Thomond. From 1543 to 1551 he was Baron Ibrickan, this title having been given him at the pacification of 1543. He was father of Conor O'Brien, third earl of Thomond [q. v.]
By his second wife Conor had Donald, Torlogh, Teige, Murrough [q. v.], and Mortogh.
[O'Donoghue's Hist. Mem. of the O'Briens, chaps. xi. xii.; The Four Masters, ed. O'Donovan, vol. ii.; Bagwell's Ireland under the Tudors, vol. i.; State Papers, i. 601, ii. and iii. passim; Cal. State Papers, Irish Ser. 1507–73; Carew MSS. 1509–74.]
O'BRIEN, CONOR, third Earl of Thomond (1534?–1581), called Groibleach, or the 'long-nailed,' eldest son of Donogh O'Brien, second earl of Thomond [see under O'Brien, Murrough, first Earl of Thomond], and Helen Butler, youngest daughter of Piers, eighth earl of Ormonde, succeeded to the earldom on the death of his father in April 1553. His right was challenged by his uncle Donnell, who was formally inaugurated O'Brien and chief of the Dal Cais. Obliged to surrender Clonroad, the usual residence of the O'Briens, Conor retired to the castle of Doonmulvihill, on the borders of Galway, where he was besieged by Donnell, but relieved by his kinsman Thomas, tenth earl of Ormonde. Subsequently Donnell petitioned for official recognition as chief of Thomond, and St. Leger, though unable to grant his request, promised to write to the queen in his favour. Matters continued in this uncertain state till the summer of 1558, when the Earl of Sussex, having marched to Limerick with a large army, caused Donnell and Teige and Donough, sons of Murrough, first earl of Thomond [q. v.], to be proclaimed traitors, and Conor to be reinstated in his possessions (Cal. Carew MSS. i. 276). Donnell took refuge with Maguire in Fermanagh, and Teige and Donough found a powerful protector in the Earl of Desmond. Peace prevailed for a brief season, and Conor won Sussex's approbation for his good execution of justice. But in 1559 Teige and Donough returned to Inchiquin, and not merely defied Conor's efforts to oust them, but, with the assistance of the Earl of Desmond, actually inflicted a sharp defeat on him and his ally, the Earl of Clanricarde, at Spancel Hill. Teige was shortly afterwards arrested by Lord-justice Fitzwilliam, and confined in Dublin Castle; but early in 1562 he managed to escape, and, being joined by Donnell, they opposed a formidable army to the Earl of Thomond. With the help of some ordnance lent him by Sussex, Thomond succeeded in wresting Ballyally and Ballycarhy from them; and eventually, in April 1565, after reducing the country to a wilderness, Donnell consented to surrender his claim to the lordship of Thomond on condition of receiving Corcomroe. War broke out again in the following year; but the resources of the combatants were exhausted, and Sidney, when he visited Limerick in April 1567, described it as utterly impoverished owing to the Earl of Thomond's ‘insufficiency to govern.’
The suspicion with which he was regarded made him discontented, and on 8 July 1569 he entered into league with the ‘arch-rebel’ James Fitzmaurice Fitzgerald (d. 1579) [q. v.] In February 1570 he attacked the president of Connaught, Sir Edward Fitton [q. v.], at Ennis, and compelled him to seek refuge in Galway. A strong force under the Earl of Ormonde was immediately despatched against him, and a few weeks later he submitted unconditionally. But being ‘seized with sorrow and regret for having surrendered his towns and prisoners,’ and determined never to ‘submit himself to the law, or to the mercy of the council of Ireland,’ he fled in the beginning of June to France. There he introduced himself on 18 July to Sir Henry Norris, baron Norris of Rycote [q. v.], the English ambassador, and, after protesting his loyalty, begged him to intercede with the queen for his pardon. Norris, who thought him a ‘barbarous man,’ wanting ‘neither vainglory or deceitfulness, and yet in his talk very simple,’ soon became aware that he was intriguing with the French court, and urged Elizabeth to coax him home at any price. Elizabeth, though she spoke of him as a ‘person of small value’ and declined to pardon him beforehand, was sufficiently alive to his power to do mischief, and promised if he returned to give his grievances a favourable hearing. But Thomond showed no disposition to leave Paris, and Norris was forced to lend him a hundred crowns and make endless promises before he would consent to take his departure.
He returned to Ireland in December, and, having made public confession of his treason to Sir Henry Sidney, he was pardoned. Subsequently, in April 1571, he made surrender of all his lands to the queen. He obtained permission to go to England to solicit their restoration, but, owing to the rebellion of the Earl of Clanricarde's sons, his presence was required in Ireland. He won the approval of the lord-deputy and council, and warrant was apparently given in June 1573 for the restoration of his lands. In December 1575 he went to Cork in order to show his respect to the lord-deputy, Sir Henry Sidney, whom he attended to Limerick and Galway, whither the principal men of Thomond repaired to