MacMurrough (Mac Murchadha), Domhnall Riabhach (d. 1476), king of Leinster, was probably second son of Gearalt MacMurrough, de facto king of Leinster, and Sadhbh, daughter of Donnchadh O'Byrne, lord of the O'Byrnes. Nothing is known of Domhnall's early life. After Gearalt's death (1431), his brother Donnchadh MacMurrough (qv) regained his position as provincial king. In 1444 war erupted between Donnchadh and his nephews, who may have had O'Byrne support. Their defeat of Donnchadh's mercenaries that year confirmed the decline of his fortunes, and they expanded their power with impunity in Leinster, attacking O'Toole in 1445. Early in 1447 Donnchadh's Butler allies suffered Domhnall's onslaught during his attack with the 7th earl of Desmond (qv) (d. 1462) on Tipperary and Kilkenny. But later that year Donnchadh came to terms with him by recognising Domhnall as his successor. This change is evident as Art, Domhnall's brother, aided Edmund Butler (qv) against the Butlers of Cahir that year. Domhnall also represented Donnchadh at the submission of the Leinster Irish to Richard (qv), duke of York (August 1449). Because of his concord with Donnchadh, Domhnall's attitude changed towards the O'Byrnes. In 1453 the two dynasties fought on opposite sides during the successful struggle of Thomas FitzGerald (qv), later 7th earl of Kildare, to wrest back the Kildare earldom from the Butlers. And later in 1454 the seneschal of the liberty of Wexford wrote that he, with O'Byrne's aid, had fended off an attack from Domhnall and Thomas FitzGerald (qv), later 8th earl of Desmond. Undeterred, Domhnall returned with Donnchadh and the Butlers and devastated the liberty.
Shortly after 1455 Donnchadh abdicated in his nephew's favour. Domhnall consolidated the alliance with the Butlers by marrying two of his children to Butler scions. For most of the 1460s he remained at peace, but joined Gerald FitzGerald's ransacking of English Leinster as reprisal for the execution (1468) of Thomas FitzGerald, then earl of Desmond, by the lord lieutenant, John Tiptoft (qv). Because of the alienation of the Leinster Irish from the English archbishopric of Dublin, Domhnall may have used his papal contacts to aid their resurrection of the bishopric of Glendalough during the early 1470s. In 1476 this successful Leinster king died, having broken a leg during a fall from a horse a year earlier. Domhnall had six recorded sons and at least one daughter. The Leinster kingship was not to return to his lineage till the death of Murchadh Ballach MacMurrough (qv) in 1511/12. That year the kingship passed to Domhnall's son Art Buidhe MacMurrough , of whom virtually nothing is known except that he died at the Franciscan friary of Enniscorthy on 25 November 1517; but his descendants, the Sliocht Airt Bhuidhe, were to be prominent in the opposition to the extension of English rule over their territory later in the century. In turn, Art Buidhe was succeeded by his brother Gearalt MacMurrough , whose succession was seemingly disputed by Murchadh Ballach's son, Muircheartach Óg. He was married to Katherine Butler but his reign was brief, lasting till his death in January 1523. Another brother, Muiris MacMurrough (d. 1531), took Gerald's place and continued the dynasty's close alliance with the Butlers, which he confirmed (August 1525) by peacefully transferring Arklow to his nephew, Sir Piers Ruadh Butler (qv).