Territory and history. With names unfamiliar, look at a map. Strabane, in County Tyrone, abuts Donegal, the County Donegal with lands that extend lands farther north than Northern Ireland. The area is at the heart of struggles between Anglo-Norman invaders, then settling in; and indigenous Irish, losing their lands. See its history from 2500 to now at http://www.strabanedc.com/history-and-heritage/early-history/
There was Christianity in Ireland before Patrick, see same site at http://www.strabanedc.com/history-and-heritage/early-history/christian/
And, in 800BC, the Milesian invasian, produced ancient names like Eoghan and Conail; geneologist.