Basically the challenge is to have an Irish Pope anytime after the Battle of Clontarf in 1014.
Challenge accepted and won: My Chaos TL has a PoD in 1200 (Genghis' early death), and ITTL our Australia has a decisive Irish-Catholic majority; at some point, the pope has to flee there, and the church gets dominated by Irish. When they find gold and gems in Australia, they also have the means to do missionary work. Current (1993) pope is Patricius XII.
Now why were there no Cardinals from Ireland till 1866?
Now why were there no Cardinals from Ireland till 1866?
For reasons I don't completely understand, only Italians were elected Pope between the Reformation and Vatican 2 (after Adrian VI and before John Paul II).
In the Middle Ages, have an Irish born priest or monk leave Ireland and become a prominent theologian at Paris or Bologna, or a senior bureaucrat in the Curia.
Now why were there no Cardinals from Ireland till 1866?
Celtic Christianity isn't a real thing, as the article itself notesThe Irish church was not consider to be standard Roman catholic for a long time. Irish church was consider to be Insular Christianity.
https://en.wikipedia.org/wiki/Celtic_Christianity
The term "Celtic Church" is deprecated by many historians as it implies a unified and identifiable entity entirely separate from the mainstream of Western Christendom...Celtic-speaking areas were part of Latin Christendom as a whole at a time in which there was significant regional variation of liturgy and structure with a general collective veneration of the Bishop of Romethat was no less intense in Celtic-speaking areas.
The Irish church was not consider to be standard Roman catholic for a long time. Irish church was consider to be Insular Christianity.
https://en.wikipedia.org/wiki/Celtic_Christianity