[2] Laurence Rehenan, Professor of Ecclesiastical History of Maynooth College, suggests that he was educated by the Franciscan Friars of Timoleague.

In 1488 Pope Innocent VIII confirmed the excommunication, at which time Mac Cárthaigh appealed the decision and a commission was set up.

[3] Returning to Munster, Mac Cárthaigh found that Gerald FitzGerald had usurped the Diocese of Cork and Cloyne with support from local rulers.

For two years, he travelled from town to village armed with the papal documents announcing his rightful appointment and absolution from any criminal charge.

It ordered that Gerald, Earl of Kildare, at that time, one of the most powerful figures in Ireland, should, with his army, protect and restore Mac Cárthaigh to his rightful place as Bishop of Cork and Cloyne.

Dressed in a coarse habit and hood and wearing the oyster shell emblem that ensured safe passage, he appeared to be very weak and worn out by fatigue.

When news of the death of bishop Mac Cárthaigh traveling in disguise spread, crowds flocked to the cathedral of Ivrea for his funeral.

They also requested any information on Mac Cárthaigh, principally because of the veneration of the people of Ivrea and the many miracles attributed to his intercession.

This request aroused great interest in Mac Cárthaigh and, after a long investigation into his life, it was decided to seek his beatification on behalf of the people and clergy of Ivrea and Cork.

The same year (1896) clerics in Ivrea agreed to donate major relics of Mac Cárthaigh to the dioceses of Cork & Ross and Cloyne.

Mac Cárthaigh was honoured with the title of "White Martyr of Munster" principally because of the intense mental and physical anguish.