Ina shaothar ''[[Foras Feasa ar Éirinn]]'' le [[Seathrún Céitinn]] scríofa as [[Gaeilge Chlasaiceach]] sa bhliain 1634,''hedéantar nasc makes explicit theidir linkchothú betweenGhormlatha Gormlaith'sagus goadingan andfógairt cogaidh a rinne Maol Mórdha.<ref>{{cite declarationbook |last=Keating |first=Geoffrey |title=Forsa Feasa ar Eirinn le Seathrun Ceitinn |year=1902 |publisher=Irish Texts Society |location=Londain |page=268 |display-authors=etal}}</ref> Pléitear fosta cén fáth a rinne Céitinn an nasc úd. Dar leis an scoláire [[Meidhbhín Ní Úrdail]], bhí Céitinn faoi thionchar ''Chronicle of warIreland'' sayingle thatMeredith herHamner, focailfoilsithe leadsa thebhliain 1633, ina deirtear go raibh "Leinsterbean kingchéile toceannaí” seekgan alliesainm inina thecúis waran againstchatha theag DálCluain Cais"Tarbh.<ref>{{cite book |last=KeatingNí Úrdail |first=GeoffreyMeidhbhin |title=ForsaCath FeasaCluana arTarbh: Eirinn'The leBattle Seathrunof CeitinnClontarf' |year=19022011 |publisher=Irish Texts Society |location=Londain |pagechapter=268Introduction |display-authorspage=etal14}}</ref>
'' As to why Keating decided to place the cause of hostilities with Gormlaith is up for some debate. One scholar, [[Meidhbhín Ní Úrdail]] suggested that he was influenced by Meredith Hamner's ''Chronicle of Ireland'' published in 1633, where the cause of Clontarf is attributed not to Gormlaith, but an anonymous "merchant's wife".<ref>{{cite book |last=Ní Úrdail |first=Meidhbhin |title=Cath Cluana Tarbh: 'The Battle of Clontarf' |year=2011 |publisher=Irish Texts Society |location=Londain |chapter=Introduction |page=14}}</ref>
Bhí tionchar ag saothar Chéitinne ar théacs eile den tréimhse úd, ''Cath Cluana Tarbh''. Níl fheictear Gormlaith ach i leagan ansin den scéal seo, ach tagann an léiriú as Foras Feasa.<ref>{{cite book |last=Ní Úrdail |title="Introduction" of Cath Cluana Tarbh |page=1}}</ref>
