Thus we see that the Leinstermen maintained a prolonged struggle to recover possession of the midland country that belonged to them under the Pentarchy when a Leinster king reigned in Tara. There are no recorded particulars of this struggle before the year 452, but from that date onward, during two-thirds of a century, fourteen battles were fought on one side or other of the border. In four of these battles, the Leinstermen were victorious. The septs of Cairbre and Fiacha, which appear so prominently in the defence of the conquered territory, were among those descendants of Niall who were settled in the lordship of lands in Meath. One Leinster dynastic sept continued to hold its territory in Meath, in submission to the new rulers. It is known by the name of Fir Tulach, "Men of the Mounds," and the name is perpetuated in that of the barony of Fartullagh in Westmeath. While this struggle was going on, another event took place, which is marked as an epoch in Irish history by the ancient annals. The event is thus related: A.D. 483. The battle of Ocha, in which Ailill Molt fell, was won by Luguid son of Loeguire and Muirchertach MacErca. From Conchobhar MacNessa to Cormac son of Art, 308 years. From Cormac to this battle, 206 years. This summing of years in the old chronicle is in direct imitation of the Chronicle of Eusebius, upon which the Irish chronicle was founded. In Eusebius, or at all events in St. Jerome's Latin translation--for the original Greek chronicle now exists only in fragments--it is customary to divide the course of history by epochs connected with great events. As each of these epochs is reached, a summary of the years between all the preceding epochs is set out. Hence we see that the chronicler from whom this entry is taken--his name is Cuanu--had in his mind three principal epochs of Irish history. The first was the reign of Conchobhar MacNessa, the celebrated king of Ulster. The second was the reign of Cormac. The third was the battle of Ocha. The epoch of Conchobhar MacNessa in the chronicle is interesting as a further proof of the primacy, so to speak, which the Ulster hero-tales acquired in the earliest age of our written literature. The reign of Cormac is an epoch, because, as I have shown in the fourth lecture, it is associated with the dissolution of the Pentarchy, the annexation of Tara to the realm of Connacht and Uisneach, and the definite beginnings of the Monarchy. What then is the epochal significance of the battle of Ocha, in which Ailill Molt, king of Ireland, is defeated and slain, and Luguid son of Loeguire and his cousin MacErca, king of the Northern Ui Néill, are the victors?