In the tenth century we find the kings of Ailech still inhabiting Ailech. In the eleventh century, the name of their domestic territory, Tír Eoghain, has been transferred from the district of Ailech to that which now bears the name, "Tyrone," which was formerly the central part of the kingdom of Oriel. I have not been able to determine how or at what time the old Tír Eoghain, now called Inis Eoghain, containing the fortress of Ailech, passed into the dominion of the kings of Tír Conaill. With regard to Oriel, there is one point to be carefully noted. In the early documents of the Anglo-Norman regime, we find the name Oriel used to comprise the present county of Louth, which is called the English Oriel, being occupied by feudal grantees. Only a very small fraction of the county belonged to the Irish kingdom of Oriel; but a few years before Strong-bow's invasion, Donnchadh O'Cearbhaill, king of Oriel, extended his dominion southward to the Boyne. It was he who, in exercise of this extended dominion, granted the lands of Mellifont to the Cistercians. This recent occupation caused the feudal newcomers to extend the name Oriel to the whole region between Oriel and the Boyne. This nomenclature may well hold good for documents of the feudal regime--but we find it used to import error and confusion into quite a different class of documents. For example, the editor of the Annals of Ulster, in his index, says that Oirghialla comprises the county of Louth, though the name is not used in that sense before the fifteenth century; and he omits to say that in the early annals Oriel comprises Tyrone and the larger part of County Derry. This method of treatment is unfortunately typical of the manner in which the sources of Irish history have been presented in publication. It is not mere anachronism. The underlying principle is that what is true of one period is true of the whole range of time covered by Irish records. When we find sympathetic editors of these records obsessed by such a view, we are still more inclined, in the case of antipathetic writers, to content ourselves with the judgment recorded by Columbanus--to deem them worthy of indulgence rather than of ridicule.