Regardless of the way that the shadowy figure of the seventh century St. Munchin is its supporter, the Diocese of Limerick truly dates from the twelfth century when its breaking points were set down at the Synod of Rathbreasail.
It is unimaginable that any diocesan structure existed before Rathbreasail; rather, the area religious chairmen would simply have been people from parsimonious gatherings in the domain.
While they would have had some prominence getting from their office, it was the abbots who held power and were administrators of the assemblage system.
The Vikings were generally responsible for the establishment of the diocesan system in Ireland.
Certainly, the city of Limerick expected a principal part in that change through made by its first religious manager, Gilbert.
Initially, he was purified as a cleric for the city and along these lines accepted accountability of the see when it was formed in the year 1111.