Óengus of Tallaght

The most important sources include internal evidence from the Félire, a later Middle Irish preface to that work, a biographic poem beginning Aíbind suide sund amne ("Delightful to sit here thus") and the entry for his feast-day inserted into the Martyrology of Tallaght.

Óengus was known as a son of Óengoba and grandson of Oíblén,[2] who is mentioned in a later genealogy as belonging to the Dál nAraidi, a ruling kindred in the north-east of Ireland.

Óengus's principal source was the Martyrology of Tallaght, an abbreviated version in prose of the Martyrologium Hieronymianum, but with a multitude of Irish saints added to their respective feast days.

The usual method of determining a terminus post quem has been to argue from the careers of saints and kings referred to in the text, many of whom remain obscure.

[6] The one thing that is usually accepted is that it was written no earlier than 797, when one of the rulers described in the prologue as having deceased, Donnchad mac Domnaill, king of Tara, died.

[9] Dumville objects that this political argument glosses over the probability that while Bran and Donnchad gave way to overlords from rival dynasties, they were nevertheless succeeded by members of their family in their own tuatha or mórthuatha.

"[11] Third, having identified a number of saints in the Martyrology of Tallaght, the primary model for the Félire, he proposes obits extending to that of Teimnén or Temnán of Linn Duachaill, who died in 828.

[12] In Dumville's view, the evidence is ambiguous, since the relationship of the extant copies of the Martyrology of Tallaght to the lost original which served as the source for the Félire is yet unclear.

Charles-Edwards, Óengus was responding to the military domination of overlords of his day, commenting that worldly glory is transient, while spiritual power is enduring.

To similar effect, Óengus also holds up the example of Máel Ruain, who continues to offer support and comfort after his death, against that of the contemporary warrior-kings Donnchadh and Bran Ardchenn, whose strong exercise of power meant no such thing after theirs.

This was a work of Northumbrian provenance, probably from Lindisfarne, which first passed through Iona and Bangor, where Irish scribes began to make some additions.

[3] His earliest biographer in the ninth century[20] relates the wonderful austerities practised by Óengus in his "desert", and though he sought to be far from the haunts of men, his fame attracted a stream of visitors.