MacMurrough (Mac Murchadha), Murchadh Ballach (d. 1511/12), king of Leinster, was son of Muircheartach mac Donnchadha MacMurrough, lord of Uí Cheinnselaig (killed during an attack on the English of Wexford, 1442). Murchadh Ballach first comes to notice when he succeeds his deceased cousin, Domhnall Riabhach MacMurrough (qv), as provincial king in 1476. His accession coincided with the rise of Gerald FitzGerald (qv), 8th earl of Kildare. In 1480 Kildare wrested Leighlin from Murchadh during an offensive against the Leinster Irish. Perhaps as a result, Murchadh sought to bolster his regional position by marrying his daughter, Ónora, to the increasingly powerful Reamainn Garbh O'Byrne (qv) of Glenmalure.
Murchadh married Joan, daughter of Edmund Butler (qv) of Polestown. After her death (1489) he seemingly did not take another wife. In 1493 he was recorded as the killer of Gerald the Lame of the MacThomas FitzGeralds of Ballysonan during a struggle with Kildare. His importance was evinced during the Perkin Warbeck (qv) crisis in 1495, when the English government granted him a fee to keep order in Leinster and entrusted Carlow castle to Gearalt, his brother and a supporter of Kildare. On the death of Gearalt (early 1496), Murchadh seems to have seized Carlow. On the return to Ireland of Kildare, now lord deputy, it required two attempts to wrest Carlow back from him. His enmity towards Kildare remained. On 19 August 1504 at Knockdoe in Galway, Murchadh fought with the O'Briens and the Burkes in their defeat by Kildare. After this reverse, he managed to preserve much of his overlordship despite Kildare's incursions up to his death in 1511/12.
Cathaoir ‘Mac na hInghine Crosda’ MacMurrough (Mac Murchadha) (a.1496–1544?), also known as Cathaoir Glas, appears to have been a nephew of Murchadh. His parentage is confused but it seems he was the son of an illegitimate sister of Kildare and Murchadh's brother Gearalt, and was born shortly before 1496. From early in his career, he actively espoused the cause of Kildare, as testified through his acceptance of several horses as gifts. On the death of Muiris MacMurrough (qv) in 1531, Gerald FitzGerald (qv), 9th earl of Kildare, secured Cathaoir's succession to the Leinster kingship in the subsequent electoral contest. During the rebellion of Thomas FitzGerald (qv), Lord Offaly and later 10th earl of Kildare, Cathaoir gave him active support. But before the rebellion's collapse, Cathaoir submitted and later (12 May 1536) entered into an indenture with the lord deputy, Leonard Grey (qv). Gradually Cathaoir's authority and position were eroded by young bloods such as Domhnall mac Cathaoir MacMurrough Kavanagh (qv) (d. c.1542) and Cathaoir mac Airt MacMurrough Kavanagh (qv) (d. 1554). On 3 September 1543 he relinquished much of his own personal power by sealing another agreement with the lord deputy, Sir Anthony St Leger (qv). Thus politically impotent, he settled down to virtual retirement, dying probably in 1544.