We have seen how the poet-historians of early Christian Ireland took over certain Latin histories of the world, especially St. Jerome’s translation of Eusebius and the history of Orosius, and adopted these as the established framework of the world’s history, thereby compelling themselves to adjust their own accounts of the Irish past to that framework. In the process of adjustment they did not all work hand in hand, and so we have different and sometimes contradictory accounts and at least half-a-dozen distinct chronologies. They found a mass of Irish traditions and legends embodied in stories long and short. They set to work on this material, endeavouring to arrange it all in sequence and to provide it with dates—the original matter being largely independent of date or sequence. This task became in fact the principal work of a certain school or class of poets, as we learn from a passage which, though found in the Book of Leinster, is held to date from about the eighth century. It is headed: “Of the Qualification of Poets.” The word translated “qualification” by O’Curry, and not inaptly so translated, is nemthigud, derived from the word nemed, the Old Celtic adjective nemetos, meaning “sacred.” A sacred place was called nemed, and a sacred person was also called nemed. The old law tract which deals with the privileges and rights of the poets is entitled Bretha Nemed, i.e., decisions regarding sacred persons. The tract in the Book of Leinster tells us that certain kinds of knowledge were necessary qualifications for certain classes of poets, in order that they might be entitled to the privileges of their class and become in that sense sacred persons, who, in virtue of the reverence due to them, might enjoy special rights and immunities. The knowledge required of them was not a knowledge of prosody or grammar, nor of chronology or geography, or any other science of the times. It was a knowledge of the stories of ancient Ireland, so thorough that they should be able to recite these stories in the presence of kings and chiefs, not a select few of the stories but scores and fifties of them. A mere memorised knowledge of the stories, however, was not sufficient, and something more than the ability to recite them to the satisfaction of courtly patrons was deemed essential to qualify the person as a poet, for the tract concludes by saying: “He is no poet who does not synchronise and adjust together all the stories.” This means clearly that it was, at the time, an essential part of the poet’s work to make a consecutive and dated history out of the sagas of antiquity.

In this way was produced a history of Ireland from the beginning down to Saint Patrick’s time. From that time onward the ancients, like ourselves, relied on the written chronicles of Ireland.

Among the written stories of antiquity, the primacy was accorded to those of the Ulster epic, Táin Bó Cuailnge and the other tales that range around it. Evidence of this primacy will be found in the oldest known Irish chronicle, in poems assigned by Meyer to the seventh century, and in the framework of the ancient genealogies. A number of modern investigators assure us that the antiquarian tradition of the Ulster sagas is marvellously true to the facts established by archæological research in regard of the age to which those sagas relate, the beginning of the Christian era. Their historical tradition was adopted without question by our medieval historians. The main fact of that historical tradition was that Ireland, in the time of Cú Chulainn, was divided into five coordinate chief kingdoms, whose kings were equal in rank and were not subordinate to a central monarchy. The old historians consequently call this period Aimser na Cóicedach (Aimsir na gCúigeadhach), the Time of the Pentarchs (the five equal kings), and leave the monarchy a blank at that time, though they profess to be able to give a list of kings of all Ireland for the earlier and later periods. This list of the pagan Monarchs of Ireland is not historical. It is compiled in a very artificial way from the pedigrees of various Irish dynasties, in a way so artificial that one name, the origin of which can be traced to the sleepy blundering of a copyist, a name which never belonged to any man, is found as the name of a king of Ireland in the list, with appropriate details telling how he acquired the sovereignty and how he lost it, and how many years he reigned. On the other hand, we are told that the fivefold division of Ireland was older than the Gaelic occupation. In fact, its origin was prehistoric, and the Pentarchy is the oldest certain fact in the political history of Ireland. That it is a certain fact, nobody who is acquainted with Irish literature and tradition will be disposed to question. To this day the word cuigeadh, “a fifth,” is in general use among speakers of Irish as the term to denote each of the principal sub-divisions of the country; and cuig cuigidh na hEireann, “the Five Fifths of Ireland,” is an expression familiar to all who speak the Irish language. This term cuigeadh, in this sense, is found in every age and generation of our written literature. And yet it is certain that throughout the whole period of our written literature, the political division of Ireland represented by this word cuigeadh, “a fifth,” and “the Five Fifths of Ireland,” had no existence. Already in St. Patrick’s time the Five Fifths were only a memory of the past. Then and for centuries afterwards, instead of five, there were seven coordinate chief kingdoms and a monarchy over them.

It is evident that a political fact which impressed itself so permanently on the vocabulary, the literature, and the folk-memory of the people for at least fifteen hundred years was not the transitory thing that appears in the lists of Irish monarchs before Christianity, a Pentarchy which lasted only during a few years and interrupted for that time the course of an earlier and later Monarchy. The details of tradition, upon examination, indicate that the Pentarchy preceded the Monarchy and lasted for a long time, long enough to become the chief outstanding fact in tradition as regards the internal political state of Ireland in the early Celtic period.

Now we come to the question, what were the five principal divisions of Ireland under the Pentarchy? In my experience, the less erudite who are interested in such matters usually answer, Ulster, Leinster, Munster, Connacht and Meath. Those who are better read in Irish history will answer, as a rule, leaving out Meath and will say that there were two Fifths comprised in Munster, and this is the teaching of Irish historians for some centuries back. In this case, it will be seen that the less learned folk are nearer to the truth.

Let us first consider what our information is regarding the Two Fifths comprised in Munster. Keating gives two alternative divisions of Munster to form the Two Fifths. In one division, the dividing line runs north and south, from Limerick to Cork Harbour. This delimitation seems to be based on the ancient extent of Munster, which did not include County Clare. The second partition of Munster, according to Keating, is by a line running from Tralee to Slieve Bloom, a very unlikely boundary, as will be evident to anyone who tries to place it on the map. The portion south of this line, we are told, was the realm of Cú Raoi, and the portion north of it was the realm of Eochaidh MacLuchta. These two names belong to the Ulster cycle, and we should expect the division connected with them to hold good in the topography of the Ulster tales, but we shall find that the Ulster tales speak of Eochaidh MacLuchta as king of all Munster and speak of Cú Raoi as a great Munster hero, but not as king of half Munster. That is not the whole story. Keating tells us that Tuathal Teachtmhar, when he became king of Ireland, established a small domestic realm for himself in the centre of Ireland, around Uisneach, by cutting off a section from each of the Five Great Fifths, and that the boundaries of all five, until his time, met at one point, the rock called Aill na Mireann, on the slope of Uisneach hill. Look at the map of Ireland, bearing in mind that the county Clare was not at that time and long after it a part of Munster, and ask yourself what possible dividing line between two kingdoms of Munster could have terminated in the hill of Uisneach, which stands ten or twelve miles westward from Mullingar.

The Five Great Fifths of Ireland are a living fact in the political framework of the stories of the Ulster Cycle. Surely then it is in those stories themselves and in the antiquity of their tradition that we must seek the evidence about these divisions, their location and extent, and not in the unreconciled statements of writers in a later age. The teaching of the Ulster stories on this matter is clear and unmistakable. It is the same throughout all of them and will be found summarised in a few sentences of the story of the Battle of Rosnaree. First we are told how this battle was caused. In the great expedition of Táin Bó Cuailnge, four of the Great Fifths had joined together for the invasion of Ulster. The invasion was not a military success, but it had secured its object, the carrying away of the Brown Bull in spite of the Ulster king, and Ulster had suffered from the ravages of war. Conchobhar, following up the retreating army of Connacht, had overtaken and defeated it on the banks of the Shannon, but he had not recovered the Brown Bull, and the other three Fifths of Ireland had got away without making any reparation for the great raid. And Conchobhar vowed that he would exact reparation or inflict punishment. He called the forces of Ulster together. These things were speedily reported to the other four Fifths of Ireland, and without delay the king of each Fifth prepared for resistance and summoned his forces to meet him at his royal seat. Here follows a recitation of the names of the four kings and their four capital places in which their armies were mustered.

The king of Tara, Cairbre Nia Fear, called out the Luaighni of Tara to meet him at Tara. It is to be remembered that in these stories Tara is not the royal seat of kings of all Ireland. There are no kings of all Ireland.

The Galians of Leinster are summoned to meet their king, Fionn File, at Dinn Riogh on the banks of the Barrow.

The Clanna Deadhadh, which is another name for the Iverni or Érainn of Munster, are summoned to meet their king, Eochaidh MacLuchta, at his royal seat of Teamhair Érann.

The muster of Connacht is held by Ailill and Meadhbh at Cruachain.

In this account of the five musters, there is no room for misconception. The author of the story was not in the slightest doubt as to the identity of the Five Fifths. His account is in complete harmony with the whole tenour of the stories relative to that age. In it, there is one Fifth of Munster, and all possibility of another is precluded. There is one Fifth of Connacht and one Fifth of Ulster. How are the two remaining Fifths constituted?

The capital of one of them is Tara, that of the other is Dinn Riogh on the Barrow. We learn from Keating and all other authorities and traditions that, in the period of Cú Chulainn and the Ulster hero tales, the river Boyne, in its lower course, separated Ulster from Leinster. Tara, on the south side of the Boyne, was in Leinster territory. Hence it is plain that Leinster and not Munster comprised two of the Five Great Fifths.

People sometimes say to me and have said to me since these lectures began, “You are very ruthless in tearing away from us some of our most cherished traditions.” Now, if I showed any contempt for tradition, this reproach would be altogether too mild. Tradition, if it is indeed tradition, is worthy of all reverence. It is not infallible. Tradition is a people’s memory, and a people’s memory, like yours or mine, has its limitations. We are all agreed that the Gaels are of Celtic origin and that their language is a Celtic language, but there is no tradition for it. From the earliest recorded traditions of Ireland and Britain down to the writing of the history of Scotland by Buchanan, not the faintest trace of such a tradition has been found. Nevertheless there are fields of historical inquiry in which tradition is the most faithful witness, and one such field is the internal polity of Ireland during the centuries that precede the written record. In that field, so far am I from despising tradition, that my main effort is to find tradition and establish its authority. We must get away from the notion that everything that is written by Keating or the Four Masters or in the Book of Invasions about that early time is tradition. The Scythian origin of the Gaels, the geographical details of their wanderings, the tower of Bregon, the landing at an unknown Inbhear Scéine—these things do not belong to tradition, they are the inventions of Latin scholars, suggested to them by ancient Latin writers.

The evidence on which I rely with regard to the Five Fifths of ancient Ireland is unquestionably traditional. The evidence that I have quoted on the point does not stand alone. It is not singular and inconsistent. On the contrary, it will be found to fit in with the whole body of ancient tradition, and taken along with the other evidences, it will be found to give life and reality to the history of an obscure yet most interesting period.

Following up the ancient testimony, we find that Cairbre Nia Fear, the king of Tara in Cú Chulainn’s time, was brother to Fionn File, the king of Dinn Riogh. Both were Leinstermen, Lagenians. Turning to the genealogies we find that the descent of all the Leinster kings in Christian times is traced from Fionn File. Tara therefore was the capital or royal seat of a Leinster kingdom, and that kingdom was one of the Great Fifths. If we look up Father Hogan’s Onomasticon, we shall see that this fact was otherwise clearly recognised. The kingdom of which Tara was the capital was named in ancient writings by the name “Cairbre’s Fifth,” Cóiced Coirpri.

Further we find that in many old documents the former existence of two Fifths belonging to the Laighin, or ruling folk of Leinster, is definitely recognised. One of these divisions is called Cúigeadh Laighean Tuadh-Gabhair and the other Cúigeadh Laighean Deas-Gabhair. These names mean that one of the Fifths lay to the north and the other to the south of a place or district called Gabhair. There were a number of places so named in various parts of Ireland, several of them in ancient Leinster. The word gabhair was evidently a topographical term having a definite meaning indicating some physical feature of the country, but I have not found it defined in any dictionary or glossary. Examining the various instances of its use in place-names and the conformation of the localities so named, I have come to the conclusion that gabhair most probably denoted a low broad ridge between two river valleys. There were two localities so named in the middle of Leinster. One was called Gabhair Life, with reference to the river Liffey. In the first poem of Duanaire Finn it is mentioned as the place where dwelt the maiden Life from whom the river, we are told, took its name: “In Gabhair between two mountains, there the modest maid abode.” This probably refers to the district of Donard in Co. Wicklow, between the waters of the Liffey and the Slaney. The two valleys are separated by a low watershed, and bounded on their outer sides by mountainous country. Westward from this, in the south of County Kildare, is a district which was anciently called Gabhair Laighean. This means Gabhair of the Lagenians, and the name suggests that it was the distinctive boundary between the two Fifths of the Lagenians. It is situated between the valleys of the Barrow, the Liffey and the Slaney, and may be regarded as the westward extension of Gabhair Life. Further evidence on the point is supplied by two glosses in the Book of Rights. One of these says that Laighin Deas-Gabhair is Ui Ceinnsealaigh, the other says it is Osraighe. I think we may take both together and regard the southern Fifth of Leinster as comprising both territories, which are represented by the dioceses of Ferns and Ossory. If O’Donovan is right in identifying Dinn Riogh with a site near Leighlin Bridge, on the bank of the Barrow, we should add to the territories named the diocese of Leighlin, which lies between Ossory and Ferns. But there is good evidence that the ancient Fifth of South Leinster was still more extensive. It extended over a considerable part of eastern Munster, taking in almost the whole county of Tipperary and a small part of County Limerick.

The territory of Ossory, we are told, stretched from Gabhrán to Grian, i.e., from the district of Gowran in County Kilkenny to the district of Pallasgreen in County Limerick.

There were several stories which explained how and why this western part of Leinster was transferred to Munster. According to one account

Osraige ö Gabrán co Gréin
tucad i n-éiric Eterscéil.

The territory of Ossory was forfeited to Munster in consequence of the slaying of Ederscél, king of Ireland, father of Conaire Mór. Ederscél was of the Ivernian race. A second account is alluded to by a poem in the Book of Rights, claiming that Ossory was rightfully subject to the kings of Munster, having been forfeited for the killing of Fergus Scannal, king of Munster. The third account is much more elaborate. It is found in the story of the Migration of the Déisi, a story which in its extant form dates from about the year 750. It tells how the Dési were expelled from the region of Tara; how one part of them crossed the sea and settled in Wales; how another part sojourned for a long time in Leinster, but at last entered the service of the king of Munster and acquired a territorial settlement by conquering and annexing to Munster the western part of the territory of Ossory. The story relates that the men of Ossory were first driven eastward over the Suir; they rallied near Clonmel and were again defeated and driven across the Anner; were followed up by the Déisi and finally forced over the Lingaun river, which to this day forms part of the boundary between Ossory and Munster. The baronies of Iffa and Offa took their name and origin from a branch of the Déisi settled in the conquered territory. West of the Suir in County Tipperary are the baronies of Upper and Lower Kilnamanagh. These were formerly O’Dwyer’s country, and the territory was ruled by the ancestors of the O’Dwyers from time immemorial. But the line of the O’Dwyers and their forefathers was an offshoot of the ruling people of South Leinster. In the genealogies, Fionn File is their ancestor, the same who was king of South Leinster in Cú Chulainn’s time. Of the same Leinster stock came the sept Ui Cuanach, whose name and territory is represented in the present barony of Coonagh in County Limerick, adjoining O’Dwyer’s country. On the western side of this territory was the district of Grian, the western limit-point of ancient Ossory.

I have found no very decisive indication of the westward extent of ancient Leinster along the southern coast. However, the story of the Déisi migration shows no distinction between the Déisi settlements south of the Suir in County Waterford and those north of the Suir in County Tipperary. There is nothing to indicate that the Munster king settled one portion of his allies on conquered territory and another portion on territory already in his possession, and the whole tenour of the story associates the settlement with the displacement and dispossession of the Men of Ossory. Therefore, I think it probable that the territory of Ossory included the greater part of County Waterford, as far west as Cappoquin and the Blackwater from Cappoquin to the sea.

As in the case of the eastern parts of Munster so in the case of the part beyond the Shannon, now County Clare, there is more than one story to account for the annexation. When several stories are given to explain a fact, though they contradict each other in the manner of the explanation, they form a strong corroboration of each other as to the fact itself. That Clare was at one time part of Connacht is the universal testimony of antiquity.

Ancient Munster, therefore, the Munster of the heroic period, comprised the counties of Cork and Kerry, the greater part of Limerick and some small area of Tipperary and Waterford. It was the smallest of the Five Great Fifths and there is no need to bisect it to form two of them. The bisecting lines mentioned by Keating, however, are not likely to have been purely imaginary. They refer in my opinion to political boundaries of a later age. We have evidence of the division of Munster in early Christian times into what may be called two distinct spheres of influence. Besides the Eoghanacht dynasty which then ruled in Cashel, there were other branches of the same dynasty ruling in various parts of Munster. Of these the most powerful was the Eoghanacht of Loch Léin, also called the Eoghanacht of Iarmuma, “West Munster.” Some of its kings are reckoned as kings of Munster, and hostile to the kings of Cashel. The dividing line from Limerick to Cork Harbour may indicate the boundary between the groups of states which acknowledged the eastern and the western authority. As regards the other line from Tralee to Slieve Bloom, I think it is founded on the fluctuating extent of the rival authority of the Dalcassian and Eoghanacht dynasties during the period between the battle of Clontarf and the Norman invasion. During that period we read of kings of the Eoghanacht lineage who are called kings of Cashel and Desmond. They are of the family of MacCarthaigh. North of the line, the power of the kings of Thomond was predominant.

The boundaries of ancient Connacht are fairly certain. The Shannon throughout its course formed the principal limit. From the head of the Shannon to the sea at Donegal Bay the boundary was nearly the same as it still is.

Between Ulster and North Leinster, the boundary ran from Loch Bóderg on the Shannon through the southern part of County Leitrim, and thence in the direction of Granard; thence by the present boundary of Ulster eastward as far as the Blackwater, down along the Blackwater to Navan and from Navan along the Boyne to the Irish Sea. On the expedition of the Táin, Medb’s army skirted this boundary, keeping on the Leinster side, until they reached the Blackwater; and the story tells how they looked across the Blackwater at “the foreign territory” (in chrich aineoil).

Such was the division of Ireland under the Pentarchy at the beginning of the Christian Era, as disclosed by the oldest traditions.

When we come to St. Patrick’s time, the fifth century, we feel ourselves within the scope of clear and definite written records. These ancient boundaries are for the most part only memories. There is no longer a Pentarchy but a Heptarchy, which remains substantially unchanged for several centuries and is described in detail by the Book of Rights, compiled about the year 900 and revised about a century later.

In this new arrangement, Munster has its present extent plus the southern angle of King’s County. Connacht has lost County Clare, but has annexed territory east of the Shannon as far as Loch Erne and Loch Ramor in County Cavan. This territory has been taken from Ulster, which no longer exists as a political unit, but is divided into three of the seven chief kingdoms. These are the kingdom of Ailech on the west, the kingdom of Ulaidh on the east, and the kingdom of Airgialla or Oriel in the middle. The Fifth of North Leinster has ceased to be a kingdom. There is only one kingdom of Leinster, which extends as far north as Dublin, the river Liffey and its tributary the Rye, which runs by Maynooth. This kingdom contains what remains of North and South Leinster and is ruled by the ancient dynasty of South Leinster.

The seventh chief realm is that of Meath which has been formed from parts of North Leinster and of Ulster. Its northern boundary is nearly but not quite the same as the present northern boundary of Leinster. It takes in part of County Cavan and excludes the northern part of County Louth, north of Ardee.

The strictly historical period in Ireland begins with St. Patrick. The authentic writings of St. Patrick are the earliest written documents of Irish history. But I do not think it would be just to say that all before that time is prehistoric. If all we had for the first four centuries of the Christian Era was a slender thread of narrative like Livy’s story of ancient Rome, we might wonder how much profit, if any, could come from examining it. We are not in so poor a case. We have a substantial mass of traditions, connected and disconnected, which, I think, enable us to supply the void of written documents in a manner that will carry conviction.

The period in question begins with the solid background of the Pentarchy. It ends with the solid foreground of the Christian Heptarchy. The problem before the student is not merely to fill up the intervening space with a random collection of traditional material, but to find out by what stages and through what causes the transformation took place; how a central monarchy came into being; how Ulster was broken up into three distinct realms; how Leinster contracted from two great kingdoms into one; how the new and powerful kingdom of Meath was established; and how Munster grew to about twice its ancient extent.

Our old native historians did not concern themselves with accounting for anything. Their chief model was Eusebius, and Eusebius was content to give lists of kings with the length of each king’s reign as the sole history of various realms of antiquity throughout centuries. So the only consecutive history we find of Ireland before St. Patrick’s time consists in like manner of regnal lists with little bits of anecdotal matter added here and there. Even these regnal lists are not authentic. They are made up artificially from pedigrees, and I have already shown that the method was so recklessly artificial as to make a king out of a misread note to one of the pedigrees. Even the oldest written history of Ireland extant follows this method. It does not indeed extend the Irish monarchy back to the Gaelic invasion. It declares the authentic history of Ireland to begin with the foundation of Emain Macha, dated 305 B.C., and it begins the Tara monarchy in A.D. 46. But from this date onward it gives the succession of the high-kings, and that succession is one of a kind unknown in the historical period. It is a succession from father to son, which is contrary to the known custom of all the insular Celts, in Ireland, Wales, and Scotland. In other words, it is again merely a pedigree converted into a dynastic succession.

When a single pedigree is utilised in this way, the fact is easily discovered. Later historians adopted a less obvious artifice, and one at the same time which made their account more widely acceptable. They shortened the reigns of the kings in the earlier history so as to leave gaps between them, and into these gaps they inserted names from other pedigrees besides that of the Tara monarchs. They took these names in turn from the genealogies of the kings of Munster, Leinster, Oriel, etc., and thus, by giving every part of Ireland a share in the monarchy, they produced a regnal history which was flattering in an all-round way and which succeeded in relegating the earlier device to comparative oblivion.

I had become familiar with this plan of transforming pedigrees into regnal lists before I first read Buchanan’s history of Scotland. In that book I found a list of forty-three kings who reigned over Scotland before Fergus of Dal Riada went over from Ireland. All the names seemed strange. They were apparently Latinised from some other language, the history being written in Latin. Were they invented, like the names in “Gulliver’s Travels,” or, if not, where were they found? Can it be, I asked myself, that the Scottish historians, like the Irish, filled the vacuum out of pedigrees? And if so, out of what pedigrees? Now it is a matter of historical record that, on the inauguration of a king of Scotland, a part of the ceremony consisted in the recitation of his pedigree, and this custom was kept up until the Dal Riada line died out with Alexander III in 1285. Therefore, I argued, the pedigree most familiar to an early Scottish historian was that of the kings of Dal Riada. I turned up this pedigree in the Irish genealogies and my conjecture was confirmed. Scotland and Ireland are all along agreed that Fergus MacEirc, an Irish prince, settled in Scotland and founded there a new kingdom and dynasty. But the forty-three kings of Scotland named before Fergus are nevertheless the forty-three ancestors of Fergus, from father to son, in the Irish genealogy. The list comprises names so well known in Irish story as Ederscél, that Munster king, whose death is said to account for the forfeiture of Leinster territory to Munster; his son Conaire Mór, whose tragic fate is told in the story of Da Derga’s Hostel; and the younger Conaire, son of Mugh Lámha, who also figures in the Irish hero-lore. All these and their forefathers, up to the eponymous Iar, head of the Ivernian stock, figure one after another in the artificial history of the first Scottish dynasty beyond the sea.

Let us get away then from such unprofitable material and let us see what comes to us in the guise of traditions of substance. We start off from the Pentarchy and the Ulster cycle. The Ulster stories have for their main basis the hostile relations between Ulster and Connacht. Being Ulster stories, they do not prolong their scope beyond a time in which Ulster has generally the best of it. Ulster’s mishaps merely serve to heighten the effect, which is Ulster’s heroism and victory. It was when this time of glory was but a memory, when Emain was a deserted site and the remnant of the Ulaidh occupied only a tiny fraction of their former territory, that these stories took their present shape and were committed to writing. We have to turn to another set of traditions, to those connected with the monarchical kindred of historical time, to learn how things developed from the stage depicted in the Ulster tales.

The course of development will be more clearly followed if it is stated in summary beforehand. The hostile relations between Ulster and Connacht continued, but the kings of Connacht grew gradually more powerful. They extended their power step by step over central-eastern Ireland, the ancient Fifth of North Leinster, and then step by step over all Ulster except what is now comprised in the counties of Down and Antrim. Upon the increase of power thus acquired they established a hegemony or primacy over all Ireland. This primacy found its definite expression in the institution of the high-kingship or Monarchy.

The first stage in the process was the occupation of Uisneach by Tuathal Teachtmhar. Who was this Tuathal? According to the genealogies he was sixth in descent from Eochu Feidlech, who was the father of Medb, queen of Connacht. Accepting Medb’s date as fixed or estimated by all our ancient writers, she flourished just at the commencement of the Christian Era. Tuathal was five generations later, and from dated Irish pedigrees we can calculate an average of almost exactly three generations to a century. Tuathal therefore would have flourished in the third quarter of the second century, say between A.D. 150 and A.D. 175. Exact dates are assigned to him in the extant regnal lists, but these lists do not agree with each other, and it is safer to rely on the law of averages. Tuathal, we are told, set up a new kingdom for himself around Uisneach. The territory surrounding Uisneach was part of the old Fifth of North Leinster. Consequently the alliance of the Four Great Fifths against Ulster was no longer operative. Tuathal was a prince of the Connacht dynasty, and his occupation of Uisneach was an invasion of North Leinster and the first stage in the break-up of the Pentarchy.

With regard to Tuathal we are told that before his birth the Rent-paying tribes throughout Ireland revolted against the Gaelic ascendancy and overthrew it. Tuathal’s mother fled to Britain and in Britain he was born. By the time he came of age the revolution had spent its force and a reaction set in. Tuathal returned to Ireland, by some he was welcomed, others he overcame by force, and he became the strongest king in Ireland. It was then that he took possession of Uisneach.

It is difficult to know what exactly to make of this story of a plebeian revolution. In its actual terms, the story is full of improbabilities, and reads like a fairy tale for children. Another difficulty about it is that a similar story is told of Tuathal’s grandfather. There is no inherent improbability in the main fact of the story, the occurrence of a plebeian revolution which for a time displaced the Gaelic ascendancy, and the occurrence of a subsequent complete reaction. Something like it happened in France little more than a century ago and in England under Oliver Cromwell. The occurrence of a revolution and the successful survival of the Connacht dynasty may help us to understand how the kings of Connacht were able afterwards to make such headway not only against their ancient rivals in Ulster but against their former allies in North Leinster; that is, if we understand that Connacht was less shaken and weakened by the revolution than the other provinces were. Again, in the Ulster stories, we hardly hear of the existence of the Picts in Ulster; they are completely dominated by the Ulaidh. But when Ireland emerges into the full light of written history, we find the Picts a very powerful people in east Ulster, Cuailnge itself, the home of the Brown Bull, and the neighbouring plain of Muirtheimhne, Cú Chulainn’s patrimony, being now Pictish territory. This may well have been the consequence of some such revolution as the story indicates.

The next stage is the occupation of Tara, the old capital of North Leinster, by Cormac, who is fourth in descent from Tuathal, and who should therefore have flourished in the period A.D. 275-300, a time corresponding closely enough with that to which the regnal lists assign him. The fact of the annexation of Tara and the surrounding region, the territory of Brega, is always glossed over by our old historians. This tacit treatment may perhaps be explained. In their histories generally, the monarchy goes back to the Gaelic invasion, and Tara is the seat of the monarchs in remote antiquity, as it actually was in the early Christian period. This location of the monarchy in Tara from time immemorial, like the assumed existence of such a monarchy, exemplifies a very common tendency, the tendency to project the known present into the unknown past.

The fact of the annexation of Tara and eastern Meath underlies the story of the Battle of Crinna. The cause of this battle, as stated, was the continued hostility of the Ulstermen to king Cormac’s line. One king after another of this line, which, be it remembered, was the Connacht dynasty and still ruled over Connacht, had fallen in fight with the Ulster enemy. Cormac had forced Ulster to give him hostages. Such hostages were by custom honourably entertained according to their rank. The Ulster hostages sat at Cormac’s own table. So unsubdued was their spirit that on one occasion they did the king the gross affront of setting fire to his beard. After this, Ulster again took up arms and drove Cormac out of Meath, forcing him to take refuge in his native realm of Connacht. There he gathered his forces and took a Munster prince, Tadhg, son of Cian, into alliance. This Tadhg figures in the genealogies as being the ancestor of a group of dynastic families which in later times ruled over certain states of Connacht, Meath and Ulster, the Luighni, Gaileanga, Cianachta, etc. These states, when we trace them back as far as possible, are native to Connacht; their branches in Meath and Ulster are frontier colonies planted to guard the conquests of the Connacht kings. Tadhg macCéin, in the story, is the personification of these colonies.

Before going into battle, Tadhg made a compact with Cormac the king. They agreed that, if Tadhg came off victorious, Cormac would grant him as much territory as he could ride around in his chariot on the day of victory.

In the battle of Crinna, Tadhg engaged the Ulstermen and completely defeated them. He himself was sorely wounded. He mounted his chariot and set out to ride around the territory he desired to win for himself and his descendants, and he commanded the charioteer to take such a course as to bring Tara within the circuit. Then, overcome with loss of blood from his many wounds, he fell into a swoon and lay unconscious in the chariot.

King Cormac had foreseen that Tadhg would try to get possession of Tara. He desired Tara for himself, and he bribed the charioteer to leave Tara out of the circuit of the ride. At intervals during the ride, Tadhg awoke from his swoon and on each occasion he asked the charioteer “Have we brought in Tara?” and the charioteer answered “Not yet.” At nightfall, Tadhg came to his senses and saw that they had reached the banks of the Liffey near Dublin. “Have we brought in Tara?” he asked again. The charioteer could not answer yes. Tadhg saw that he had been cheated, and he slew the charioteer.

Now the territory that fell to Tadhg’s share in the story extended along the coast from Ardee to Dublin and inland along the northern frontier of Meath to Loch Ramor—and these territories in later times were occupied by the Connacht colonies whose rulers claimed descent from Tadhg. Roughly speaking the whole stretch of country forms an L inverted and in the angle of this L stands Tara the ancient capital of North Leinster, but henceforth the capital of Cormac’s kingdom.

Except this story of the Battle of Crinna, there is no other story or even title of a story known to me which explains how Tara ceased to be the seat of the North Leinster kings and passed into the possession of the kings of Connacht and Uisneach. There is no other account which explains why or how the Leinster frontier, which formerly lay along the Boyne and the Blackwater, was afterwards pushed back to the Liffey and the Rye. The territory which fell to Tadhg was partly Ulster territory and partly Leinster territory. Yet in the story itself, there is no mention of Leinster and Cormac’s only enemies were the Ulstermen. The story, which in its extant form belongs to a very late period, is evidently defective. It is written in conformity with the theory that the Monarchy existed before the Pentarchy and that Tara was the seat of the Monarchy from time immemorial. Consequently it ignores what we may call the Leinster aspect of the matter, and the conflict seems to be altogether between Cormac and Ulster. Ulster lost land on the north side of the Boyne, and this conquered territory, under the compact, fell to the share of Tadhg. The underlying notion, in this episode of the chariot-ride, is obviously that the victor is to be rewarded with a share of the spoils. If, then, the conquered part of Ulster formed part of his reward, and if in the same bargain he gained part of Leinster between the Boyne and the Liffey, and if he expected to gain Tara, we must, I think, infer that this part of Leinster and Tara likewise were no less conquered territory than the piece of Ulster that fell to Tadhg.

Therefore, there should have been an earlier version of the story, now lost, which showed that not Ulster alone but North Leinster also resisted Cormac and suffered defeat from him and his ally. Such an account would explain, what remains a complete blank, so far as I know, in this traditional history, how the dynasty of North Leinster came to an end and how Tara and Bregia, south as well as north of the Boyne, passed into the possession of the kings of Connacht and Uisneach.

The reign of Cormac is regarded in our earliest histories as an epoch in Irish history. This, I think, was because it marked the end of the Pentarchy and the rise of the Monarchy seated at Tara.

The next stage in the growth of the Connacht power brings us to the overthrow of the Ulster kingdom and the conquest of the greater part of Ulster. In the century after Cormac, his descendant Muiredach Tireach becomes king of Tara. Muiredach, we are told, in his youth took command for his father, Fiacha Sroibhtine, king of Tara, and was successful in establishing his father’s authority in southern Ireland. His uncles, the three Collas, became jealous of his success. The young prince, they said, will be chosen king when his father dies, and we shall be shut out from the succession. They then conspired to overthrow their brother and win the kingship for one of themselves while Muiredach was still absent in the South. They raised an army against the king. Fiacha consulted his druid. The druid answered:

You have two alternatives. You can be victorious. If you are, the kingship will pass from your son and your descendants. But if you are defeated and slain, your son and your posterity will rule Ireland. It is the symbol in Irish story of the Triumph of Failure. The king said, Then I choose defeat and death. The three Collas were victorious, the king fell in the fight. Then all Ireland arose against the victors. Muiredach was chosen king, and the Collas were banished over the sea. They dwelt in exile for some years in Britain, but the guilt of their brother’s blood oppressed their souls, and at last they said, We can bear it no longer, we shall go back to Ireland and lay down our lives for our crime. The young king forgave them and took them to his favour. After this, they spoke to him one day and said: Though thou and we are at peace, our sons will grow up and contend with thy sons for the kingship. Give us a kingdom for ourselves and our posterity. It shall be so, said the king. What part of Ireland will you give us? said they. The Ulstermen, said the king, have ever been hostile towards me and towards our fathers. Go and conquer their kingdom, and it shall be yours.

The Collas then went to Connacht, which was still the homeland of the new Tara dynasty, raised an army there, invaded Ulster, were victorious, and captured the Ulster capital. The conquered territory comprised the present counties of Armagh, Monaghan, Tyrone, and the greater part of Fermanagh and Derry.

I wish to dwell on the fact that the conquerors were princes of the Connacht dynasty, then ruling also in Tara. Their army was drawn from Connacht. In fact, all this chain of events is the direct sequel of the old rivalry between Connacht and Ulster that forms the basis of Táin Bó Cuailnge and the Ulster cycle in general. The inhabitants of the conquered parts of Ulster got the significant name of Airgialla, Oirghialla, “the eastern subjects.” In relation to Meath and Tara, they were northern not eastern subjects. The name Airgialla then is based on the fact that the conquering power at the time when the name came into use was still regarded as the western power, its home was Connacht.

Thus ended the Fifth of Ulster. Let us see what was happening meanwhile in southern Ireland. In Munster, under the Pentarchy, the kings of the Érainn or Iverni held rule. In St. Patrick’s time, these no longer ruled in Munster. The kings of Munster belonged to a distinct line, called the Eoghanachta. Their capital was no longer in the west. It was Cashel, not far from the eastern border of their kingdom and in territory formerly part of Leinster. To the original extent of the Munster Fifth had been added in the meantime the counties of Clare and Tipperary, a small part of Limerick, and the larger part of Waterford, making the bounds of Munster almost but not exactly what they are at present.

In face of the growing power of the kings of Connacht, how it came about that Clare was detached from Connacht and added to Munster, I cannot explain to my own satisfaction, beyond saying that, within a smaller scope, the Eoghanacht kings of Munster became even more powerful than the kings of Connacht and ruled over a more firmly consolidated realm. During the early Christian centuries, before the Norse invasions, Munster appears to have enjoyed greater tranquillity than any other realm in Western Europe. The genealogies show that there was an early Eoghanacht settlement in the Clare area, called Eoghanacht Ninuis, and another, still called Eoghanacht, in the island of Arainn Mhór, to the north of Clare.

There were at least two accounts in ancient story of the transfer of Clare to Munster. The time of this event differs by centuries in the two stories, and I shall not endeavour to reconcile them or to choose between them. There are three distinct accounts of the eastern annexation from South Leinster. The only one of these that is full and explanatory, and that fits with the known later stage of things, is the account connected with the Migration of the Déisi.

Let it be noted that Cashel, the seat of the Munster kings in Christian times, stands outside of ancient Munster. Keating relates an ancient story telling how Cashel was “discovered” in the time of Corc, king of Munster, i.e., about A.D. 400, and got a new name. This new name was a Latin one, for Caiseal is the Irish representative of the Latin word castellum, “fortress.” These things show how late was the use of Cashel as the seat of Munster sovereignty.

What and whence was this new ruling power in Munster, the Eoghanachta? Their genealogies show that at one time they were worshippers of a god named Segomo—one of their ancestors is named Nia Segomon, “Segomo’s champion.” This god Segomo is unknown to Irish tradition, in which his name is never found outside of the Eoghanacht genealogy. He was known, however, and worshipped in Gaul, where he is commemorated in several inscriptions of the Roman period. He was a war-god and is equated, according to the fashion of Roman Gaul, with the Latin god Mars—”Deus Mars Segomo.” The descendants of Segomo’s Champion are named in three Ogham inscriptions, all found in the district of Dungarvan and Ardmore, on the southern seaboard. The indications therefore are that the Eoghanachta represent a relatively late Gaulish settlement in that part of Ireland. The story of the Déisi Migration mentions several bodies of Gaulish settlers.

The Migration of the Déisi is an evident sequel of the conquest of Tara and eastern Meath under Cormac. Déisi means “vassal communities.” These particular vassal communities dwelt around Tara, and were possibly identical with the Luaighni, who formed the chief fighting force of North Leinster in Cú Chulainn’s time. They quarrelled with Cormac, we are told, and he drove them, or a large part of them, out of Meath. They migrated in two bodies. One body crossed the sea and settled in southern Wales where the descendants of their princes still held sway in the eighth century. The other body settled for a time in Leinster.

Later on this Leinster section entered into an alliance with the Eoghanacht king, Oengus, whose queen was the daughter of their chief. By their aid, Oengus conquered what is now the south-eastern part of Munster, and he settled the Déisi as frontier colonists on the conquered territory. Oengus flourished in St. Patrick’s time, the second and third quarter of the fifth century.

The loss of the large territories about the Boyne and the Suir reduced Leinster to much smaller dimensions. What remained of the two ancient Fifths was now united in one kingdom, ruled over by the line of the ancient kings of South Leinster. This reduction and unification means the final passing away of the Pentarchy described in the Ulster tales. The seat of the Leinster kings is no longer either Tara or Dinn Riogh, but Ailinn, which lies between them, on the southern side of the Curragh of Kildare.

The Connacht kings continued, however, to extend their conquests and their power. A grandson of Muiredach Tirech was king of Tara at the beginning of the fifth century (c. A.D. 400), Niall of the Nine Hostages. His brother, Brión (or Brian) took possession of a south-western section of Ulster, comprising a large part of the counties of Leitrim and Cavan, afterwards called Brian’s Land—Tír Briúin. Three sons of Niall took possession of what remained of western Ulster, now comprised in the county of Donegal. Their names were Eoghan, Conall, and ‘Enda, and the territories occupied by them were called Eoghan’s Land, Conall’s Land, and ‘Enda’s land.

Another son of Niall, named Coirbre, obtained a piece of Leinster, now the barony of Carbury in Co. Kildare.

The Connacht dynasty and its branches now ruled over the northern half of Ireland, with the exception of the eastern seaboard region from Ardee to the Giant’s Causeway. It ruled in Tara, and its chief kings were recognised also as Monarchs of Ireland.

The Connacht power, after the time of Niall, was regarded as comprising three chief divisions—the kingdom of Connacht, the Airgialla, and the territory of the descendants of Niall (Uí Néill). All Leinster was laid under tribute to them, and a note in the Book of Leinster says that this Leinster tribute was divided equally among the three sections. This subdivision of the Connacht power, in my opinion, was what gave rise to the ancient term Teora Connachta, “the Three Connachts”—a term which seems to have caused some trouble for its explanation to writers of a later age.

An unpublished tract in the Book of Lecan, also found in the introductory part of the Book of Genealogies by MacFir Bhisigh, tells us that during this period, the succession to the Monarchy was regulated in this way: On the death of the Ardri, the king of Connacht took his place as king of Tara. A new king of the same family was elected in Connacht, and this process went on during several generations. Niall was king of Connacht first, of Tara afterwards. And so, in like manner, the high kingship was filled from Connacht until the death of Ailill Molt in A.D. 483 or thereabouts.

The two facts, then, that explain the transformation of the Pentarchy at the beginning of the Christian Era into the Monarchy and seven principal kingdoms of St. Patrick’s time, are these: In the northern half of Ireland, the gradual conquest achieved by the Connacht dynasty; in southern Ireland, the rise of a new power, that of the Eoghanacht kings, centred in Cashel. Along with the direct control of northern Ireland, the Connacht dynasty obtained predominance over the country in general, and this predominance found its natural expression in the high kingship.

Between the establishment of the Connacht dynasty in East Meath and in Tara, the ancient seat of the North Leinster kings, and the overthrow of the Ulster kingdom, there is a period of more than half a century, during which the Ulster power stood at bay. Of this state of things we have a very remarkable record, not written on paper, but graven on the face of the country. The Ulster kings endeavoured to defend themselves against further aggression by fortifying their entire frontier except where it was already protected by strong natural obstacles such as lakes, forests or broad rivers. Linking these natural barriers they raised a massive earthern rampart which, with these barriers, formed a continuous line of defences from the Irish Sea on the east to Donegal Bay on the west. Details of the extant remains of this Great Wall of Ulster and of the popular traditions connected with it will be found in Mr. Kane’s paper on the Black Pig’s Dyke in the Proceedings of the Royal Irish Academy. These details I am able to supplement with others, but it would be out of place to go into particulars in such a historical sketch as the present. What I wish to bring under special notice is this—that the Ulster frontier was fortified alike against Meath and Connacht—a further illustration of the fact that during that period Meath and Connacht were politically united under one dynastic power.