Cahir mac Art Kavanagh, "The MacMurrough" and King of Leinster, also Lord of St. Molyns, and baron of Ballyann (died 1554), was an Irish magnate of the Tudor period.
He renewed his submission to Sir Anthony St. Leger in November 1540, and preferred a request to be allowed to hold his land in feudal tenure.
[1] His assumption of the title of Mac Murrough aroused the suspicion of Sir Edward Bellingham, which was further increased by his refusal, 'sticking to the Brehon law of restitution', to hang one of his followers for horse-stealing.
: Brian, who married a daughter of Hugh Mac Shane O'Byrne; Tirrelagh, who married a sister of Robert Browne of Mulrankan, in the barony of Bargy, Co. Wexford, whose tragic fate is narrated in Holinshed; Crean, Moriertagh, Art, and Dermot, who for his good and faithful services was, on 18 March 1555, appointed tanist to the chieftaincy of the clan.
Cahir Mac Art Caomhánach is an interesting figure in Irish history as the founder of an estate which, notwithstanding the vicissitudes of land tenure in Ireland, still remains in the possession of his lineal descendants.