In the list of dioceses there is an omission which demands explanation. No mention whatever is made of Dublin, the oldest diocese in Ireland. Not only so; the northern limit of the diocese of Glendalough is marked by Lambay Island and Greenogue, which lies due west of it in the County Meath. Thus the diocese of Glendalough, as contemplated by the Synod--and, it may be added, as it was in fact forty years later[57]--included the whole of the actually existing diocese of Dublin. The Danish Christians of Dublin and their Irish bishop are treated as interlopers; they are absolutely ignored. It may be said that this was due to the mutual hostility which divided the diocese of Dublin from the native Church, and to the fact that the bishops of Dublin had always been subject to Canterbury. But it is not enough to say this; for the estrangement of Dublin from the Irish is the very thing that has to be accounted for. It had its root in the growing prosperity of the Danish city. The Irish had no towns. Town life was introduced among them by the Norsemen. And of their towns Dublin was always the chief. By this time it had become so important that it had good right to be called the metropolis of the country. And its citizens were thoroughly aware of this. As early as 1074 the burgesses of Dublin and their bishop, Patrick, claimed for it that title.[58] Now in all reason a metropolis should have a metropolitan as its bishop; and no doubt the bishops of Dublin thought themselves _de facto_, if not _de jure_, superior to the other bishops of Ireland. In fact we find one of them playing the archbishop. We have two interesting letters of Anselm, written apparently about 1100. One of them is addressed to Malchus, bishop of Waterford, directing him to rebuke Samuel O'Hanley, bishop of Dublin, for various irregularities, in particular for having his cross carried before him like an archbishop; the other is addressed to Samuel himself, and complains of the same actions.[59] These proceedings are not likely to have been brought to an end by Anselm's letters; and we may assume that they were continued as long as Samuel held the see of Dublin. It was but natural that Cellach should strongly resent them, for they were disrespectful both to himself and to the archbishop of Cashel. We are not surprised, therefore, to find that on the death of Samuel in 1121, eleven years after Rathbreasail, Cellach tried to get possession of the Church of Dublin,[60] most probably with the intention of bringing it under the jurisdiction of the bishop of Glendalough. Nor are we surprised that the men of Dublin at once replied by electing another bishop and bidding Ralph of Canterbury to consecrate him if he desired to retain the suffragan see which they had so long preserved for him.[61] We shall see hereafter how the bishops of Dublin were at length induced to look with favour on the Irish Church. Meanwhile we learn that they were not very