Tuathal came at a strategic moment. The Ulster Cycle shows quite clearly a struggle between Connacht and Uladh for the hegemony of the five provinces of Ireland. The earlier parts of that cycle (though written to exploit Uladh) show that hegemony claimed and won by Connacht; the later parts show it passing to Uladh. Then there is a dark period, in which we have no literature to guide us and for which the records in the Annals of Tigernach give little help. During this time occurs the mysterious episode known as the Revolt of the Vassals. Whatever that episode meant, it appears that Tuathal’s mother had to fly the country. He himself returned later to his province of Connacht to resume the dynastic struggle with the kings of Uladh for the rule of Ireland. Probably Tuathal was the Irish prince to whom Tacitus refers as being for a time with the Roman legions in Britain. The dates are approximate; and Tuathal’s first act on his return to Ireland suggests that he had not misspent his time. Fighting in Ireland prior to this time had mainly been that of contests between famous warriors, or from chariots. Henceforward it becomes that of trained legions existing as a standing militia. For Tuathal established the Fianna Eireann; and by means of this new weapon he restored the hegemony to Connacht. It is right briefly to trace this dynastic struggle between Connacht and Uladh, because out of it, and out of the needs it created and the problems it raised, grew the national State. Tuathal, king of Connacht, with his palace at Cruachan Ai, came east to Uisneach, and from there exercised the hegemony of Ireland. It is said that he took the “necks” of the four provinces where they touched one another, and in each “neck” held a national festival for each quarter of the year. At Tara a special festival was held, at which the Brehons discussed and collated the laws, and at which the local rulers discussed and compared the local administration of the country. In other words, a general tendency towards uniformity was set up because of a direct central authority; and it was undoubtedly because of this tendency that Tuathal’s son, Fedhlimidh, who succeeded him, received the title of Reachtmhar, the Law-giver. Tuathal, however, did not come east to Tara, except to the festival. Tara was the seat of the kings of Leinster, with an elder glory and significance attaching to it that it is not easy to explain in any critical use of the materials available. It was not for a century after Tuathal that the Connacian dynasty, in the person of Cormac, established itself at Tara and compelled the kings of Leinster to make their headquarters elsewhere at Naas. Then the central authority took a fresh accession of strength, and a definite and distinctive polity began to emerge, with the looser system that till then had prevailed tightened up and made uniform in all its parts.