Tadhg Mac Cárthaigh (Latinised and anglicised Thaddeus McCarthy) c. 1455 – 25 October 1492, was an Irish ecclesiastic. He was a bishop who never ruled his see, even though he was appointed to two of them: Bishop of Ross, Ireland in 1482 and Bishop of Cork and Cloyne in 1490. His feast day is 25 October.
Early life
Mac Cárthaigh was born in 1455 at Innishannon in County Cork. His father was the lord of Muskerry and his mother was reputedly the daughter of Edmund Fitzmaurice, ninth Lord of Kerry. It is probably the case that he belonged to the sept of the MacCarthy Reagh of Carbery. Laurence Rehenan, Professor of Ecclesiastical History of Maynooth College, suggests that he was educated by the Franciscan Friars of Timoleague.
Mac Cárthaigh studied for the priesthood under an uncle, Canon Thady Mac Cárthaigh and continued his studies in Paris with another relative, Professor Don Raymond, at Paris University. He was ordained in Cork by Bishop William Roche and travelled to Rome afterwards to continue his studies. At this stage in Irish history there was no single political entity. There were Gaelic kings and Anglo lords. It may have happened that news had reached Rome of the death of Bishop Hugh either innocently or through political intrigue.
A lengthy dispute broke out between the Mac Cárthaigh and O'Driscoll dynasties over who was the rightful bishop of Ross, during which the O'Driscolls made many false accusations against Mac Cárthaigh. Bishop O'Driscoll assumed Thaddeus was an imposter and complained to Rome. In 1485 Henry VII became king of England and lord of Ireland, and his party wanted to have its own representative as bishop of Ross. Mac Cárthaigh was declared an intruder and excommunicated. In 1488 Pope Innocent VIII confirmed the excommunication, at which time Mac Cárthaigh appealed the decision and a commission was set up. The commission found in his favour, and the excommunication was nullified. He was then appointed Bishop of Cork and Cloyne on 21 April 1490.
Death
Fourteen weeks later, Mac Cárthaigh arrived at Ivrea having presumably walked from Rome. On the evening of 24 October 1492, a lone pilgrim arrived on foot at the hostel for pilgrims. 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. The warden of the hostel gave the exhausted traveler a hospitable welcome and a place to rest for the night. At dawn, a strange and mysterious light was observed coming from his room. On entering, the warden discovered the body of the pilgrim illuminated by a beautiful radiance of light. Tadhg Mac Cárthaigh was 37 years old.
In 1896 Pope Leo XIII confirmed the immemorial cult of the "Blessed Thaddeus". The same year (1896) clerics in Ivrea agreed to donate major relics of Mac Cárthaigh to the dioceses of Cork & Ross and Cloyne. These relics can now be found in The Church of The Immaculate Conception The Lough, Cork North Cathedral, Cobh Cathedral and St Mary's Parish Church in Youghal. His feast day of 25 October is kept in the dioceses of Ross, Cork, and Cloyne, and in Ivrea, where he was buried.
Mac Cárthaigh was honoured with the title of "White Martyr of Munster" principally because of the intense mental and physical anguish.