A verbal resemblance in the names led some Irish writers, from the close of the eighteenth century down to O'Curry, to identify the Atecotti with the Irish Aithech-thuatha, the ancient Rent-paying communities referred to in my third lecture. I do not think that the philologists will sanction the identification so far as it is based on verbal resemblance. The name Atecotti has not been found in any form in the native records of Ireland or Britain as the name of any nation or sub-nation or in the topography of either island. Nevertheless contemporary evidence during the second half of the fourth century shows that not only on the frontier of Roman Britain but also on the Continent there was a numerous and warlike collection of men known by this name. As in the case of the name Scotti, the conclusion I would draw is that Atecotti was a name for a general class of men not for a particular nation, tribe, or political community. The name, in its best authenticated form, is a Celtic word, consisting of the adjective cottos preceded by the prefix ate. Cottos means "old," or "ancient." The prefix ate, which becomes aith or ath in Irish of the MS. period, means "back" or "again," like the Latin re, and like this, too, it often has a strengthening or intensifying force. Thus, Atecotti may be taken to mean the very ancient, the primitive, the pristine folk; and so it is explained by Whitley Stokes. Who then were these very ancient people who were associated with the Scotti and were not identified with the Picts? We are reminded at once of the Irish traditions of non-Gaelic and pre-Gaelic communities which formed the main fighting strength of the kings of North Leinster and South Leinster, and of the non-Gaelic origin ascribed to Cú Chulainn, Fear Diadh, and to the kindred of Fionn mac Cumhaill and of Goll mac Morna. Of course, on this point we are far from complete certainty, but the probability, in my opinion, is that, when the Irish went to war in the fourth century, they still adhered to the politico-social distinction between the Gaelic ascendancy and the conquered plebeian race, and that this was the distinction between the Scotti and the Atecotti. The adjective cottos does not appear to belong to the vocabulary of Irish, but it is found in the various Brittanic dialects and was a frequent element in Gaulish nomenclature. The Atecotti, therefore, probably received their name not in Ireland but in Britain or Gaul. The view I put forward reaches, but by a different path, a similar conclusion to that adopted by the Irish writers who sought to identify the Atecotti by name with the plebeian communities of ancient Ireland, the Aitheach-thuatha.
Contact with the Roman military system reacted on the domestic condition of Ireland. To this cause we may ascribe the origin of the Fiana as a definite military organisation at a definite period. The word fian is collective, signifying a band of fighting men, not merely a band of men called out upon occasion for military service, but a permanent fighting force. From it is derived feindid, feinnidh, a professional soldier. Normally, the ancient nations depended in warfare on their citizen soldiers who in time of peace were engaged in the works of peace. The great imperial states, for their plans of conquest and dominion, or for the protection of their artificial realms, relied on standing armies. In the stories of the Ulster cycle, though, as we have seen, there are certain castes or communities with a special tradition of warlike service and efficiency, there does not seem to be any permanent military organisation. The cycle of the Fiana, on the contrary, is concerned with fighting men whose principal occupation is warfare. The two epic traditions are quite distinct. Chariot-fighting is characteristic of the Ulster tales. The Fiana fight on foot. The time to which the Fiana belong is the time of the conquests made by the Connacht kings in North Leinster, the time of Conn, Art, Cormac, and Cairbre Lifeachar—roughly speaking, the third century of the Christian era. During that century, the Britons were "accustomed to war with Irish enemies," and the Irish therefore had opportunities of learning something of the Roman manner of warfare and military organisation. Again, to the third century and later belong those great earthen frontier walls in Ireland spoken of in the foregoing lecture. The erection of these walls, we may well believe, was inspired by acquaintance with the Roman frontier fortifications in northern Britain, constructed in the second century and in the early part of the third century.
Accustomed to military life, numbers of the Scotti and Atecotti took service under Roman commanders, especially under Stilicho, who enlisted troops wherever he could raise them to defend the Empire against the Goths. The time was during the last years of the fourth century and the opening years of the fifth. A number of Latin inscriptions on the Continent bear witness to the existence, in the later days of the Western Empire, of a military force in the Imperial service under the name of Primi Scotti—"the First Scots." The majority of these inscriptions are found near the ancient frontier between the Roman Empire and western Germany, showing that the Scots or Irish were engaged to defend the line of the Rhine against the Germans. A few of the inscriptions are found in the interior of Roman Gaul.
About the same time, under the emperor Honorius and his general Stilicho, a number of distinct bodies—cohorts or regiments—of the Atecotti served in the Imperial armies. The military records known as Notitiae Dignitatum have mention of the following forces: Atecotti seniores; Atecotti juniores; Atecotti Honoriani seniores; Atecotti Honoriani juniores; and Atecotti Gallicani juniores; to which by implication we must add Atecotti Gallicani seniores. All these were serving in the Western Empire, and in addition to these there was a body called simply Atecotti serving in the Eastern Empire. Those in the west formed part of a force which included also Moors, Germans, and others drawn from countries outside of the Empire. The general name for these troops appears to have been Honoriani, from the emperor Honorius in whose service they were enlisted. The chief military task of the Roman armies under Honorius was to resist the Goths who were threatening to overrun his dominions. The Spanish historian Orosius, who lived in Spain at that time, calls the barbarian forces of Honorius the Honoriaci, i.e., he substitutes a Celtic form for the Latin Honoriani. (St. Patrick, a little later, uses a similar Celtic form Hiberionaci, instead of the usual Latin name Hiberni, for the Irish.) In 409, the year before the capture of Rome by the Goths under Alaric, the German nations of the Suevi, Vandals, and Alans overran southern Gaul as far as the Spanish borders. The passes of the Pyrenees were held at this time by the Honoriani. Orosius says that, on the approach of the Germans, the Honoriani in the Pyrenees made common cause with them, and shared with them in the invasion of Spain and the partition of the conquered territory. He adds that the Honorians were more clement than the Germans towards the conquered people, and extended some degree of protection and assistance to them. This conquest was of short duration. A few years later the Goths in turn invaded Spain and established a Gothic kingdom over it.
These events belong to a period for which Ireland has no contemporary documents of history, but for which, as it borders on the more strictly historical period, Irish traditions have their highest validity in evidence. The testimony of native tradition, as we might expect, is in accord with that of external history.
The third and fourth centuries of the Christian era were a time in which nearly all the peoples of Europe outside of the Roman Empire were, so to speak, on the march with arms in their hands. At the beginning of the Christian era and before it, we have seen that this state of unrest already pervaded the Celts and Germans of Mid-Europe. A few centuries earlier still, the Celts almost alone are found in this condition of warlike mobility; for the radiation of the Celtic migratory movements in every direction—southward into Italy, westward into Gaul, Spain, Britain, and Ireland, northward into the Baltic basin, and eastward along the Danube valley and into Asia Minor—is evidence that, unlike the movements which led to the break-up of the Western Empire, the earlier Celtic migrations were not accompanied by pressure from other moving populations on their borders.
I have ascribed the early expansion of the Celts to iron. The possession of iron had a two-fold effect. The natural condition of the greater part of Europe is forest. If man were absent or idle-handed, nearly all Europe in a few generations would revert to the forest state. To clear the land of woods, or even to prevent the fresh growth of woods after clearance, the implements of the Stone Age, Early and Late, cannot have been effective. Even let us suppose that large clearances could have been made by burning, at once the thickets would again spring up, and under their protection the forest trees. Nor can the possession of bronze have sufficed to subdue the natural tendency towards forest. Bronze, in the Bronze Age, was not the industrial material of the many; it belonged to the privileged few who were not hewers of wood. Iron, when it came, introduced an industrial revolution relatively greater than that which has been introduced in modern times by the steam-engine. Once people knew how to work it, iron was abundant enough to be in the hands of every worker. Iron became and has ever since remained the sole master of growing wood. With the conquest of the forests came a great extension of tillage. Iron not only cleared fertile tracts but tilled them more rapidly and deeply than was possible with the wooden spade which, as the old Irish copper mines have taught us, was the digging implement of the Bronze Age. Thus food became abundant, and with it a density of population which, before iron, was possible only in fertile and forestless regions like the flood areas of Egypt and Mesopotamia. Road making, too, progressed, and the use of vehicles. As iron furnished the many with better implements of work, it furnished them also with better implements of war. An overflowing population and warlike arms for all—here we have the conditions for migratory conquest. On these conditions the Celtic migrations were based. The spread of these conditions to the Germans led to the later Germanic expansion, and their further spread brought about the Slavonic and Turanian migrations which drove the Germans down upon the subject peoples of Rome, peoples whose power of resistance and will to defend themselves had been already broken by that Roman policy so frankly described by Tacitus.
Just as the universal subjection of science and invention to the purposes of warfare has reduced Europe to its present condition, so the universal possession of iron made Europe in the third and fourth centuries a scene of universal war. Though Ireland was fortunately untouched by the great migratory movements of the Continent in that age, these movements reacted on Ireland by weakening the neighbouring provinces of the Empire.
The raids on Britain and Gaul for booty and captives—raids from which, as I have argued, the Irish got their new name of Scots—were followed by Irish settlements on various points of the British coast. The conquest of eastern Meath or Bregia by the kings of Connacht and Uisneach forced a part of the population to migrate, and one body of the migrants settled in Demetia, in the south of Wales. We can safely place the conquest of Bregia in the second half of the third century, but it does not follow that the settlement in Wales was made at the same time, for the story of the Déisi migration makes it appear that the expelled population remained for many years in Leinster before the settlement in Munster. There may have been a similar delay before their kindred crossed over to Wales.