According to this, Cummascach mac Cathail of the Uí Cremthainn, king of the Airgíalla, expelled Niall's confessor Éogan Mainistrech from Armagh, installing his own half-brother, Artrí mac Conchobair, who may have been the son of High King Conchobar mac Donnchada, as abbot of Armagh.
According to this information, Cummascach mac Cathail, king of the Airgíalla from the Uí Cremthainn lineage, expelled Niall's confessor Éogan Mainistrech from Armagh and installed his own half-brother, Artrí mac Conchobair, who could have been the son of High King Conchobar mac Donnchada, as abbot of Armagh.