MacMurrough Kavanagh, Domhnall (c.1520–1542?), Gaelic warlord, was eldest son among five sons and a daughter of Cathaoir Kavanagh (d. 1526), leader of the MacMurrough Kavanagh branch of Sliocht Muircheartaigh Óig, based at Garryhill, Co. Carlow. His particular family had strong connections with the earls of Kildare, having accepted the Fitzgeralds’ superiority in the early sixteenth century, after the unsuccessful attempts of Domhnall's great-grandfather Murchadh Ballach MacMurrough (qv) (d. 1512), king of Leinster, to resist them.
On 19 August 1504 Murchadh Ballach and his allies, the O'Briens and the Burkes of Clanricard, had been defeated by Gerald Fitzgerald (qv) (d. 1513), 8th earl of Kildare, at Knockdoe, Co. Galway. No doubt this reverse convinced Murchadh Ballach that he should reach an accommodation with the earl. This seems to have been borne out when Kildare in April 1509 bought the castle of Dromroe (Mount Loftus, Co. Kilkenny) from Theobald fitz Robert Butler. Soon afterwards, it appears, the Fitzgeralds entrusted the castle to a sympathetic MacMurrough – most probably Domhnall's father, Cathaoir, as is suggested by the fact that Cathaoir accepted a horse from the 9th earl of Kildare in 1522.
The first major incident that is known of Domhnall's life came in 1526, when his father was surprised at Dromroe by his rival Cathaoir MacMurrough Kavanagh (qv). In a ruthlessly effective attack, Cathaoir mac Airt's followers torched the castle, burning to death its inhabitants, who included Domhnall's father, his grandmother, and a kinswoman. Cathaoir mac Airt's merciless act left Domhnall and his siblings orphans, spawning a circle of revenge and counter-strike. And it is likely that the orphans were returned to their kinsmen in Garryhill to rebuild their lives.
It was in the aftermath of the collapse of the Kildare suzerainty in 1535 that Domhnall began to emerge as a powerful young warlord. Like his cousin Seán O'Byrne (qv), lord of Crioch Raghnuill, Domhnall was to ally with the ambitious Toirdhealbhach O'Toole (qv), lord of the O'Tooles. Toirdhealbhach was determined to spread his influence through much of east Leinster, to the detriment of the government and the more traditionally senior Irish families. The ambition of these more hard-line Irish leaders led to major government campaigns against them during May 1539 and June 1540. After Toirdhealbhach and Domhnall in June 1540 forced the retreat of government forces from O'Toole's country, Domhnall – fuelled with the confidence of youth – grew brazen in his attacks. Later that June he sacked Athy and burned the house of the Dominicans.
But Domhnall's spree of attacks was coming to an end. The sack of Athy proved to be the final straw for James Butler (qv) (d. 1546), 9th earl of Ormond. In July 1540 the earl and his forces swept into the MacMurrough heartland of Idrone, devastating it and rendering the MacMurroughs unable to put up an effective resistance. Most of the MacMurroughs took the prudent option and gave Ormond hostages – all except Domhnall. This stubbornness spurred Ormond to write to Henry VIII, describing Domhnall as ‘a wilde young man, that hath of late doon moche hurtes to your majestie subjectes, having nothing to lose and adherith to Tirrellagh OTole’. Still Domhnall faced certain defeat, leading him to dispatch messengers to Toirdhealbhach, telling him to make haste with as many forces as he could muster. Toirdhealbhach obliged, arriving duly on the borders of Idrone, but balked when he viewed the size of the Butler forces. Deciding that discretion was the better part of valour, Toirdhealbhach negotiated a truce for himself, leaving Domhnall to his own devices. The truce expired in September 1540, leading Sir Anthony St Leger (qv) to campaign against the O'Byrnes and the MacMurroughs, including Domhnall, forcing them to submit before bringing Toirdhealbhach to book that November.
With Toirdhealbhach's submission, Domhnall resolved to move closer to Ormond and his party in east Leinster, a move that produced immediate results. That November Ormond included Domhnall in his plans for the reform of Leinster, proposing that he, with other Butler clients, be made second pensioners. But nothing came of these plans. The last mention of Domhnall was on 29 June 1541, when his followers killed Cetach Ruadh O'More, lord of Laois. That no mention was made of him thereafter suggests that he may have died some time in 1542. Even though he must have been barely into his twenties, he made a profound impression in a brief but bloody career. He fathered four sons and a daughter.
Domhnall was succeeded as leader of the Sliocht Muircheartaigh Oig by his brother Gerald Kavanagh (c.1522–1549). After the death of Cathaoir mac na hInghine Crosda (‘MacInnycross’) MacMurrough (qv) (d. c.1544), this Gerald pressed his claims to be recognised as the most powerful of the MacMurrough Kavanaghs. This course led him directly into conflict with Cathaoir mac Airt MacMurrough, his father's murderer. In 1545 this bitter rivalry was settled decisively in a pitched battle at Hacketstown, Co. Carlow. Even though Gerald had the support of his Gabhal Raghnaill O'Byrne cousins, the issue was bloodily settled in favour of Cathaoir mac Airt, leaving Gerald to lick his wounds. Thereafter Gerald became a peripheral figure in MacMurrough politics, although he was attainted of committing some felonies on 10 January 1549. Some time after this he died, leaving one son, Domhnall mac Gerald Kavanagh (d. p.1571).