O'Carroll (Ó Cearbhaill), Maolruanaidh (d. 1532), king of Éile (Ely O'Carroll), was son of Seaán O'Carroll (qv), king of Éile, and probably Mary Butler, sister of Edmund MacRichard Butler (qv) of Polestown. While nothing is recorded of Maolruanaidh's youth or early manhood, it seems he acted as a loyal lieutenant for his father. After the killing of Seaán by Desmond forces in 1489, Maolruanaidh succeeded his father as king of Éile. Maolruanaidh's loyalty, like Seaán's, was to the absentee 7th earl of Ormond, Sir Thomas Butler (qv). Moreover, this attachment to Ormond placed Maolruanaidh at odds with Gerald FitzGerald (qv), 8th earl of Kildare and lord deputy of Ireland. Maolruanaidh's hostility to Kildare was no doubt increased by the fact that the FitzGerald enemy Sir James Butler (qv) of Ormond was fostered in his household. While Maolruanaidh was on a collision course with Kildare in the early 1490s, the determination of Henry VII and Ormond to restrain the rising power of Kildare brought the crisis in the midlands to a head. On 6 December 1491 the king appointed Sir James and Capt. Thomas Garth (fl. 1495) as commanders of a royal army to crush rebels in the counties of Kilkenny and Tipperary, allowing them to act without reference to Kildare. On his return to Ireland, Sir James found a ready support base amongst the O'Carrolls, MacWilliam Burkes, and O'Briens. By winter 1492 the struggle between Sir James and Kildare had developed into a range war throughout Leinster and the midlands, including Éile. In 1492/3 Maolruanaidh wrote to Henry VII, complaining that Kildare had devastated his lordship because he had supported Sir James as the king had directed. This hostility to Kildare was to persist into the sixteenth century. And in August 1504 Maolruanaidh travelled to Galway to join a confederation of Kildare's enemies led by the Clanricard Burkes, Toirdhealbhach Donn O'Brien (qv) and Murchadh Ballach MacMurrough (qv). The constitution of this alliance was decidedly midland in character, including (besides the O'Carrolls) the O'Brien and O'Kennedy lords of Arra and Ormond. But Kildare's victory on 19 August 1504 at Knockdoe over this confederation effectively crushed opposition to Kildare in Leinster and the midlands for much of the early 1500s. It may have been in the years that followed Knockdoe that Maolruanaidh married Joan FitzGerald, sister of Kildare. What followed was an uneasy peace, as there still existed considerable antagonism between Kildare and the O'Carrolls, which quickly re-emerged after Toirdhealbhach Donn O'Brien's mauling of Kildare's army in Limerick (1510).
The O'Brien victory redefined the political landscape of the midlands, shaking the FitzGerald hegemony. Shock waves can be detected among the O'Connors of Offaly in 1511, while Kildare campaigned against Maolruanaidh and the O'Mores in 1513. In August that year Kildare's troops killed Maolruanaidh's son Seaán at the siege of the O'Carroll castle of Leap. However, the earl's artillery failed to reduce Leap, forcing him to go home for reinforcements. On his return journey Kildare was shot by the O'Mores; his wound proved fatal, causing his death on 3 September. A rapprochement may then have been hammered out between Maolruanaidh and Kildare's son and successor Gerald FitzGerald (qv), 9th earl of Kildare. This would seem to have been the case, as the MacMurroughs and the O'Carrolls accompanied Sir Piers Butler (qv) to burn the Desmond lands in the Limerick barony of Connelloe late in 1513, although this may have been an independent political manoeuvre by Sir Piers to exploit the political vacuum emerging in the midlands. However, Kildare in 1514 moved to shore up his midland affinity, attacking the O'Mores and capturing Cullentragh castle and Abbeyleix. He also lent his support to Sir Piers to drive off the FitzGeralds of Desmond, who now had the support of Maolruanaidh. In spite of the success of Kildare and Sir Piers, Maolruanaidh still managed to extract a black rent from the English of Tipperary and Kilkenny in 1515.
The relationship between Kildare and Sir Piers steadily declined after the death of Ormond in 1515. An outright rupture between the two was still some way off, allowing them to give each other assistance against the midland Irish. During 1516 Kildare defeated Maolruanaidh, taking Leap castle. Again in 1517 their axis proved too strong, when Kildare quashed Maolruanaidh after he had attacked the FitzGerald clients among the O'Melaghlins of Offaly and Westmeath, while Sir Piers forced the Butlers of Cahir to submit to his authority. Kildare's victory saw Maolruanaidh change tack and acknowledge FitzGerald supremacy over the midlands. However, the political map of the midlands and of Ireland was changing rapidly because of the deadly feud emerging between Sir Piers and Kildare. Significantly, once they fell out the Kildare overlordship in the midlands began to falter, affecting Kildare's governance of Ireland. When Thomas Howard (qv), earl of Surrey, became lord lieutenant in 1520, he embarked on a series of campaigns throughout Ireland. Among Kildare's clients opposing Surrey's army were Maolruanaidh, Conall O'More (qv), a noble of Laois, and Brian O'Connor Faly (qv) of Offaly. Surrey's suspicions of Kildare's involvement were confirmed when Maolruanaidh affirmed them at a July parley before handing over his brother Donnchadh O'Carroll (d. 1538) and his own son, Fearganainm (see below), as hostages. Moreover, Donnchadh, in a statement that September, told government officials that the abbot of Monasterevin had brought letters to Maolruanaidh from Kildare in England during Easter 1520, encouraging him to war on the earl's English enemies. These amicable relations were brief. With Kildare still out of favour and in England, Sir Piers (under the cover of extending royal authority) sought to spread his influence in the midlands. In 1521 he attacked Éile, capturing Fearganainm. But in July 1521 Maolruanaidh, with the O'Mores and O'Connors of Offaly, raided Co. Kildare, forcing Surrey to lead an inconclusive campaign against them. By mid October they again submitted. However, the growth of Sir Piers's power among the midland lords convinced Maolruanaidh to place himself in the Butler camp. When Kildare returned to Ireland (January 1523) he immediately began to repair the frayed position of his dynasty countrywide. However, he could not prevent west Leinster and the midlands from becoming in 1525 the vital arena for his struggle with Sir Piers. In response to the resurgent Kildare, Sir Piers dispatched gunners to Maolruanaidh in Easter 1525 to defend Leap. But Kildare and O'Connor Faly had the best of the conflict in the midlands, forcing Maolruanaidh to renew his alliance with the earl. This briefly reestablished Kildare's midland suzerainty. Maolruanaidh was in an unenviable position, as he was caught between the conflicting ambits of the two great families. However, he displayed his shrewdness, attempting to play one off against the other. In addition, in the 1520s he began to copperfasten his dynasty's position, sealing two politically advantageous marriages. His heir Fearganainm was married off to a daughter of Kildare, renewing close ties with the FitzGeralds, while the hand of Gráinne, Maolruanaidh's daughter, was given to Ulick Burke (qv), later 1st earl of Clanricarde, Sir Piers's nephew. And when Burke tried to back out of the marriage, Maolruanaidh exerted his impressive strength and coerced him into keeping his word.
For much of the late 1520s Maolruanaidh flitted between the rival camps. In October 1528 he, along with Conall O'More and Cathaoir O'Connor Faly, attended the investiture of Sir Piers, now earl of Ossory, as lord deputy. Maolruanaidh, however, was to return quickly to the Kildare cause, forcing Ossory to promote his rivals. Henry VIII's appointment (5 July 1532) of Kildare as lord deputy, to succeed Sir William Skeffington (qv), strengthened Maolruanaidh against Ossory's machinations. It was also to Maolruanaidh's advantage that Kildare, incapable of sharing power, set out, under the pretext of good government, to reestablish himself over the midlands. And it was in the strategic midland theatre that the struggle between Ossory and Kildare reached a deadly climax, focusing on the race in 1532 to succeed Maolruanaidh. Before he died, Maolruanaidh nominated his son Fearganainm O'Carroll (Ó Cearbhaill) (c.1490–1540) as his successor. This was vehemently resisted by Maolruanaidh's brothers, Donnchadh and Uaithne. Their resistance was actively encouraged by Ossory, compelling Fearganainm to require Kildare's support in 1532–3. The conflict in the midlands and Éile propelled Kildare and Ossory to outright war. In 1533, during the successful siege of Birr castle by Kildare and Fearganainm, the lord deputy was badly wounded by a shot from Ossory's O'Carroll clients. But Kildare's power restablished Fearganainm in his lordship, bringing Donnchadh to heel in 1534 by taking Shinrone castle. The demise of Donnchadh prompted Uaithne to challenge Fearganainm for the lordship. Fearganainm's position was further complicated by the recall of Kildare to England in early 1534, and the subsequent rebellion in June of his son Thomas FitzGerald (qv), later 10th earl of Kildare. Throughout the doomed Kildare rebellion of 1534–5, Fearganainm loyally supported his brother-in-law, while Donnchadh fought with the Butlers and the English forces. Indeed, Donnchadh's persistence paid off in 1536 as he, with Butler support, eliminated the challenge of Uaithne and deposed Fearganainm, who did not regain his position till Donnchadh's death after May 1538, following the campaign by the lord deputy, Sir Leonard Grey (qv). With regard to Fearganainm, Grey cultivated his government's budding midland influence by lending military assistance to him against Ossory's clients in June–July 1538. Grey took Birr and Modreeny castles, but promptly handed them over to Fearganainm. Fearful for his security, Fearganainm then ruthlessly hunted down his dynastic rivals and formed an alliance with James Fitzgerald (qv), 14th earl of Desmond, giving him his sister to wife. As a preamble to his restoration, Fearganainm had agreed with Grey at Dublin (12 June 1538) to hold his lordship as a tenant of the king. Fearganainm moved even closer to Grey and his government in 1539, making a treaty which determined the O'Carroll overlord's relationship with the Tudor crown. By its terms, Fearganainm was to pay a fixed rent for his lordship and agreed to provide a fixed number of soldiers each year for the king's service. In return Grey enforced the shaky peace between the O'Carroll factions, taking Modreeny castle in November from the sons of Donnchadh. Grey's favour of Fearganainm and other former Kildare clients such as Brian O'Connor Faly returned to haunt him. To the Butlers, Grey's efforts were tantamount to a rejection of their efforts to oust the Kildares from their near monopoly of the lord deputyship. In late 1539 Grey's enemies, led by James Butler (qv), 9th earl of Ormond, directly accused him of favouring former FitzGerald clients and of being under the influence of Fearganainm and Brian O'Connor Faly in particular. The recall (April 1540) and subsequent fall of Grey hastened Fearganainm's end. In either late spring or early summer Donnchadh's son Tadhg O'Carroll, with the O'Molloys, slipped through a secret tunnel into Fearganainm's principal residence, Clonlisk castle. There they found the aged and now blind Fearganainm and (after he had put up a brave fight) butchered him. He left two sons, Tadhg Caoch O'Carroll (qv) and William Odhar O'Carroll (qv).