Gormlaith (d. 1030), daughter of Murchad and allegedly queen consort in turn to the kings of Dublin, Tara, and Munster, belonged to the Uí Fháeláin lineage of northern Leinster. Her father, Murchad son of Finn, died in 972 as king of Leinster; her mother apparently belonged to a Connacht dynasty. Gormlaith was a sister of Máel-mórda (qv) son of Murchad, who was appointed to the kingship of Leinster in 1003 by Brian Bórama (qv). Like her earlier namesake, Gormlaith (qv) daughter of Flann Sinna (qv), this Gormlaith is credited with three marriages, attesting Uí Fháeláin's involvement at the highest level of dynastic politics during this period. The role of Gormlaith in three marriage alliances certainly appears to be historical, and presumably illustrates the political ambition of Uí Fháeláin.
Gormlaith's first marriage, contracted probably in the late 960s when she was in her mid teens, was to Amlaíb (Óláfr) Cuarán (qv) king of Dublin, whose Hiberno-Scandinavian dynasty at that time still exercised a fitful suzerainty over northern Leinster. She was the mother of Amlaíb's son Sitriuc Silkbeard (qv), later king of Dublin. It is not certain if Gormlaith and Amlaíb were divorced or if she was widowed by his death (981). In any event, she was later (probably in the late 980s) the wife of Brian Bórama and, before their divorce, bore him a son, Donnchad (qv) (d. 1064). The case for her having meanwhile married Máel-Sechnaill (qv) (d. 1022) king of Tara – much less having borne his son Conchobar (d. 1030) – rests, however, on weaker foundations. This marriage is not mentioned in the ‘Banshenchas’ (lore of women); evidence for it comes only from a poem in the Book of Leinster genealogies, which refers to Gormlaith's marriages as ‘three leaps’, at Dublin, Tara, and Cashel. A commentary on the poem names Máel-Sechnaill as her second husband. While serial marriage was certainly commonplace in Irish dynastic circles, the claim that Gormlaith was thrice married may have been a fiction inspired by sovereignty symbolism.
Medieval literature accords Gormlaith an important role in court intrigue. While it is not implausible that assertive female dynasts involved themselves in politics behind the scenes, the nature of the available evidence makes it difficult to assess the historicity of specific claims. The twelfth-century Ua Briain propaganda work ‘Cogadh Gáedhel re Gallaibh’ portrays Gormlaith as a destructive influence in events leading to the battle of Clontarf – as does the lost Hiberno-Norse ‘Brian's saga’, episodes from which feature in the medieval Icelandic ‘Njal's saga’. It is maintained that she carried a grudge against her ex-husband Brian Bórama, and incited her brother Máel-mórda and her son Sitriuc to rebel against Munster overlordship. It is further claimed that she persuaded the Dublin leadership to recruit the viking fleet of Brodir (qv) from the Isle of Man. While the Irish and Norse versions of Gormlaith's intrigues differ in detail, and are perhaps indebted to literary embellishment, the agreement of both traditions on the general circumstances of her involvement suggests that they have some basis in fact. Gormlaith outlived all three of her alleged husbands; she died in 1030 aged probably in her late seventies.