a special channel for Roman influence to trickle into the free island. The chief influence was the infiltration of the Christian religion. The adoption of this religion by the Imperial government in the fourth century must have had, as we have seen, a sensible effect in conferring prestige on Christianity beyond the boundaries of the Empire. It became inevitable that the favoured creed should henceforth be closely associated with the Empire in the idea of barbarians and regarded as the Roman religion. Hence that religion acquired, on political grounds, a higher claim on their attention. [Sidenote: KING LOIGAIRE] We must realise the force of these general considerations in order to understand the policy of the High King who sat on the throne of Ireland throughout the whole period of Patrick’s work in the island. Loigaire had succeeded about five years before Patrick’s arrival (A.D. 428). He was son of King Niall, who had been slain in Britain, perhaps in the very year in which Patrick had been carried into captivity. Niall’s immediate successor was his nephew, Dathi, who reigned for twenty-three years, and likewise found death beyond the sea.[84] But Dathi, it would seem, went forth as a friend, not as a foe, of Rome. He led a host to help the Roman general Aetius to drive back the Franks from the frontiers of eastern Gaul, and he was struck by lightning. The expedition of Dathi has an interest not only from the Irish, but also from the Roman point of view. It illustrates the wide view of Aetius. It shows us how he looked to all quarters for mercenary help; if he relied on the Huns, whom he was hereafter to smite so hard, he also invited auxiliaries from Scottia. From the Irish side, it illustrates the fact that Ireland was within the Roman horizon. [Sidenote: REIGN OF KING LOIGAIRE] The reign of Loigaire lasted thirty-six years, and it marks a new epoch in Irish history. The part which Loigaire himself played in bringing about this change has been underrated. His statesmanship has been obscured by tradition, but is revealed by interrogation of the scanty evidence. The first difficulty is one which meets us at all stages of early Irish history. It is impossible to determine the compass of the power and authority of the High Kings in the under-kingdoms. It seems probable that Loigaire was able to exercise as much influence, at least in northern Ireland, as was permitted to any king by the political and social organisation of the country. We have seen that the efforts of his grandfather, Eochaid, and his father, Niall, had extended the power of the family throughout a great part of north Ireland. His cousin, Amolngaid, was king of Connaught. His brothers and half-brothers were petty kings.[85]