During the battle he received a life-threatening head wound, and was afterwards carried to the abbey of Tomregan, County Cavan to be healed in the house of its abbot, Saint Bricín.
The Suidigud Tellaig Temra recounts that because of his vast store of lore, when Diarmait mac Cerbaill wished to establish the original boundaries of Tara, he had recourse to Cenn Fáelad.
[4] His verses were all composed in quatrains of numbered syllables with regular rhyme, and moderate use of alliteration, in contrast to a more archaic form that was still practised in the south of Ireland at the time (i.e., Leinster and Munster).
He was the first poet quoted in the Irish annals, being referred to as sapiens, a technical term denoting a head teacher or professor in a monastic school (though not necessarily a monk himself).
Robin Flower stated "How far these are really his may be a matter of controversy, but there can be little real doubt that the writings by him existed in the period when the vernacular learning was being eagerly cultivated."