If the question be asked, By whose authority or influence this division of Meath into dioceses was made? I can suggest no one more likely than Máel Muire Ua Dunáin, the "bishop of Meath" to whom reference has already been made.[34] He was a Meath man, and probably bishop of Clonard: he was an ecclesiastic of great repute, especially in the north; and he was a devoted adherent of the Reform movement. His action, if indeed it was his, was premature and ill-advised. As we shall see, his work had to be slowly undone. But it is remarkable, as the first attempt known to us to establish diocesan episcopacy among the Irish. I shall have more to say about it hereafter; but now I must follow the main stream of events.
Gilbert,[35] the first bishop of Limerick, as has already been noted, was an Irishman. Indeed, we may venture to describe him as one of the most remarkable Irishmen of his time, in spite of the fact that the Annals pass him by in almost complete silence. He was at any rate a staunch supporter, or, as we should rather say, the leader of the Reformation movement in its earliest course. In a letter written in 1107 Anselm exhorted him, in virtue of their mutual friendship, to make good use of his episcopal office by correcting that which was amiss, and planting and sowing good customs, calling to aid him in the work his king (Murtough O'Brien), the other Irish bishops, and all whom he could persuade.[36] That, assuredly, Gilbert was forward to do.
No sooner had he taken possession of his see than he began to organize a diocese. Its boundaries seem to have been fixed with care. It was exactly co-extensive with the modern diocese of Limerick, except on the north, where it stretched across the Shannon and included part of the present diocese of Killaloe.[37] Moreover he made the Church of St. Mary his Cathedral Church; indeed it is not unlikely that he built it to serve that purpose.
A few years later he was appointed Legate of the Holy See. It is manifest that his new office gave him a unique opportunity of moulding the fortunes of the Irish Church. In Ireland Gilbert was now virtually the chief prelate and head of the Church. He was the representative and embodiment of the authority of the Holy See. The whole Romanizing party would naturally circle round him as their leader, and many waverers would be attracted to the new movement in the Irish Church, by the claim which he could make to speak in the name of the head of the Church Catholic.