During his time as Archbishop he had to adjudicate in a dispute within the Diocese of Kilmore. When he held his first Provincial Council at Drogheda in July 1480, an objection was raised to the appointment of Cormac Mág Shamhradháin because he was illegitimate. This appointment was revoked on 20 October 1480 and Tomás Mac Brádaigh, the Archdeacon of Kilmore, recommended: his decision was confirmed by Pope Sixtus IV.
- 'The Register of Octavian de Palatio, Archbishop of Armagh 1478-1513' f. 385
- "Pope Sixtus IV." Butler, Richard Urban: The Catholic Encyclopedia. Vol. 14. New York: Robert Appleton Company, 1912