That such a movement actually took place in the twelfth century is beyond doubt. From about the year 1200 on it is certain that the organization of the Church of Ireland was similar to that of the other Churches of western Christendom. The country was divided into dioceses; and each diocese had a bishop as its ruler, and a Cathedral Church in which the bishop's stool was placed. The Cathedral Church, moreover, had a chapter of clergy, regular or secular, who performed important functions in the diocese. But up to the end of the eleventh century all these things were unknown among the Irish. The constitution of the Church was then of an entirely different type, one that had no exact parallel elsewhere. The passage from the older to the newer organization must have taken place in the twelfth century. During that century, therefore, there was a Reformation in the Irish Church, however little we may know of its causes or its process. But this Reformation was no mere re-modelling of the hierarchy. It can be shown that it imposed on the members of the Church a new standard of sexual morality; if we believe contemporary writers, it restored to their proper place such rites as Confession, Confirmation and Matrimony; it substituted for the offices of divine service previously in use those of the Roman Church; it introduced the custom of paying tithes; it established in Ireland the monastic orders of Latin Christendom[1]; and it may have produced changes in other directions.[2] But I propose to confine myself to the change in the constitution of the Church, which was its most striking feature. The subject, even thus narrowed, will give us more than can be satisfactorily treated in a few pages.