Áed (982/3–1056), son of Cróngille Ua Foirréid and bishop and scholar at Armagh, belonged, like many bishops of Armagh, to the Cenél nÉogain, the most powerful of the dynasties of the Northern Uí Néill. He is best known as the subject of the poem ‘Uasal epscop Éirenn Áed’: here the unnamed poet, broadly hinting that he hopes to be rewarded for his composition with a horn filled with ale, devotes twenty-two out of thirty-three quatrains to Áed before proceeding to speak of other Armagh dignitaries and notable ecclesiastics. From the persons named it is possible to assign the poem a date between 1032 and 1046, perhaps no later than 1042. Áed is praised for his piety, austerity, and chastity in terms that may derive some of their emphasis from the fact that the supreme authority in Armagh, the abbot and ‘successor of Patrick [qv]’, was at this period a married layman. Áed is also commended for his scholarship (‘sage of the west of Europe’), and described as the founder of a ‘great school’. His devotion to his pastoral duties is reflected in the epithets ‘horseman of the gospel among the laity’, and ‘instructor of the layfolk’.
In 1049 the abbot Amalgaid (qv) died and was succeeded by his brother Dub-dá-Leithe (qv), who up till then had served as fer léigind (lector or chief scholar) at Armagh. Dub-dá-Leithe's place as fer léigind was in turn taken by Áed. Various considerations suggest the reasons for this appointment: the words of Áed's eulogist, whatever exaggeration they may contain, surely reflect a significant degree of intellectual achievement; and other members of Áed's kindred, the Uí Fhoirréid, are spoken of in the annals as distinguished scholars.
Áed's assumption of this second office suggests that the fer léigind was a more important figure in Armagh than the bishop: an intriguing sidelight on that church's priorities at this time. It is not clear whether Áed relinquished his episcopal status on becoming fer léigind, or exercised both functions jointly. His obituary notice in the annals calls him only ‘chief fer léigind of Armagh’; but a marginal verse describes him as both ‘aged scholar’ and ‘gentle bishop’.