The Kings of Airghialla (Oirghialla or ancient Armagh)

The kin from whom Gillabride, Somhairlidh‘s father, sought assistance.  As chiefs, or the derbfine of Airghialla (Orghialla or Oriel) both Gillabride and Cu Caisil Ua Cerbhaill shared a common royal ancestor Gobraidh mac Fearghus according to the Irish Annals.  Clan Donald tradition states that Gillabride went to his kin in Ireland to obtain an army to battle Viking raiders.  The Annals of Ireland confirm the relationship.  From 

695, Maol Fothartaigh, mac Maolduibh, [descent from Carpri Daim Argait] tigherna na n-Airghiall, died.
825, Cumascach son of Cathal, lord of Airghialla. [Sil Duibthiri of clann Colla Uais]
832, Artri mac Conchobhar, brother of the King of Oirghialla, Abbot of Ard Macha, died.
835, Gobraidh, mac Fearghus , chief of Oirghialla, went to Alba, to strengthen the Dal Riada, at the request of Cinaeth, son of Ailpin.
850, Fogartach son of Mael Bresail, lord of Oirghialla, died.
851, Maelcaurarda, son of Maelbreasail, lord of Ui Mic Uais Oirghiall, died.
852, Fogertach m. Maele Bresail, rex na n-Airghialla, died.
882, Maelpadraig, son of Maelcuararda, lord of Airghialla, was slain by the Airghialla themselves.
1101, Cu Caisil Ua Cerbhaill, tigherna Fernmhaighe & Oirghiall.
1119, Flaithbertach Ua Laidhgnen ri Fernmhuighi (Fernmaighe, Fermoy).