The early Milesian invaders left their names just as closely imprinted upon our topography as did their predecessors the Tuatha De Danann. The great plain of Bregia in Meath was so called from Brega, son of that Breogan who built Brigantia. Slieve Cualann in Wicklow—now hideously and absurdly called the Great Sugar Loaf!—is named from Cuala, another son of Breogan; Slieve Bladhma, or Bloom, is called from another son of the same; and from yet another is named the Plain of Muirthemni, where was fought the great battle in which fell Cuchulain "fortissimus heros Scotorum." The south of Munster is called Corca Luighe from Lughaidh, son of Ith, nephew of Milesius. The harbour of Drogheda was called Inver Colpa, from Colpa of the sword, another son of Milesius, who was there drowned when trying to effect a landing. The Carlingford Mountains were called Slieve Cualgni, and a well-known mountain in Armagh Slieve Fuad, from two more sons of Breogan of Brigantia, slain after the second battle with the Tuatha De Danann, while they followed up the chase. The sandhills in the west of Munster, where Donn, the eldest son of Milesius, was shipwrecked and lost his life—as did his whole crew consisting as is said of twenty-four warriors, five chiefs, twelve women, four servants, eight rowers, and fifty youths-in-training—is called Donn's House. So vivid is this tradition even still, that we find a Munster poet as late as the last century addressing a poem to this Donn as the tutelary divinity of the place, and asking him to take him into his sidh [shee] or fairy mound and become his patron. This poem is remarkable, as showing that in popular opinion the early Milesians shared the character of sub-gods, fairies, or beings of supernatural power, in common with the Tuatha De Danann themselves, for the poet treats him as still living and reigning in state, as peer of Angus of the Boyne, and cousin of Cliona, queen of the Munster fairies.[11] Wherever he turned the Gael was thus confronted with scenes from his own past, or with customs—like the August games at Tailltin—deliberately established to perpetuate them.
In process of time, partly perhaps through the rationalising influences of a growing civilisation, but chiefly through the direct action of Christianity, with which he came into active contact in perhaps the fourth, or certainly in the fifth century, the remembrance of the old Gaelic theogony, and the old Gaelic deities and his religious belief in them became blunted, and although no small quantity of matter that is purely pagan, and an immense amount of matter, but slightly tinged with Christianity, has been handed down to us, yet gods, heroes, and men have been so far brought to a common level, that it is next to impossible at first sight to disentangle them or to say which is which.
Very probably there was, even before the introduction of Christianity, no sharply-defined line of demarcation drawn between gods and heroes, that, in the words of Pindar, ἓν ἀνδρῶν ἓν θεῶν γένος, "one was the race of gods and men," and when in after times the early mythical history of Ireland came to be committed to parchment, its historians saw in the Irish pantheon nothing but a collection of human beings. It is thus, no doubt, that we find the Fomorians and the Tuatha De Danann posing as real people, whilst in reality it is more than likely that they figured in the scheme of Gaelic mythology as races of beneficent gods and of evil deities, or at least as races of superhuman power.
The early Irish writers who redacted the mythical history of the country were no doubt imbued with the spirit of the so-called Greek "logographers," who, when collecting the Grecian myths from the poets, desired, while not eliminating the miraculous, yet to smooth away all startling discrepancies and present them in a readable and, as it were, a historical series.[12] Others no doubt wished to rationalise the early myths so far as they conveniently could, as even Herodotus shows an inclination to do with regard to the Greek marvels; and the later annalists and poets of the Irish went as far as ever went Euhemerus, reducing gods and heroes alike to the level of common men.
We find Keating, who composed in Irish his Forus Feasa or History, in the first half of the seventeenth century, and who only re-writes or abbreviates what he found before him in the ancient books of the Gaels now lost, distracted between his desire to euhemerise—in other words, to make mere men of the gods and heroes—and his unflinching fidelity to his ancient texts. Thus he professes to give the names of "the most famous and noble persons of the Tuatha De Danann," and amongst them he mentions "the six sons of Delbaeth, son of Ogma, namely, Fiacadh, Ollamh, Indaei, Brian, Iuchar, and Iucharba,"[13] but in another place he quotes this verse from some of his ancient sources—
"Brian Iucharba and the great Iuchar,
The three gods of the sacred race of Dana,
Fell at Mana on the resistless sea
By the hand of Lughaidh, son of Ethlenn."
These whom the ancient verse distinctly designates as gods, Keating makes merely "noble persons," but at the very same time in treating of the De Danann he interpolates amongst his list of their notable men and women this curious sentence:[14] "The following are the names of three of their goddesses, viz., Badhbh [Bive], Macha, and Morighan."[15]
There are many allusions to the old Irish pantheon in Cormac's Glossary, which is a compilation of the ninth or tenth century explanatory of expressions which had even at that early date become obscure or obsolete, and many of these are evidently of pagan origin. Cormac describes Ana as mater deorum hibernensium, the mother of the Irish gods, and he adds, "Well used she to nourish the gods, it is from her name is said 'anæ,' i.e., abundance, and from her name is called the two paps of Ana." Buanann, says Cormac, was the "nurse of heroes," as "Anu was mother of the gods, so Buanann was mother of the 'Fiann.'" Etán was nurse of the poets. Brigit, of which we have now made a kind of national Christian name, was in pagan times a female poet, daughter of the Dagda. Her divinity is evident from what Cormac says of her, namely, that "she was a goddess whom poets worshipped, for very great and very noble was her superintendence, therefore call they her goddess of poets by this name, whose sisters were Brigit, woman of smith-work, and Brigit, woman of healing, namely, goddesses—from whose names Brigit[16] was with all Irishmen called a goddess," i.e., the terms "Brigit" and "goddess" were synonymous (?) The name itself he derives fancifully from the words breo-shaighit, "fiery arrow," as though the inspirations of a poet pierced like fiery arrows. Diancécht Cormac calls "the sage of the leech-craft of Ireland," but in the next line we read that he was so called because he was "Dia na cécht," i.e., Deus salutis, or god of health. Zeuss quotes an incantation to this god from a manuscript which is, he says, at least a thousand years old. His daughter was Etán, an artificer, one of whose sayings is quoted by Cormac. Néith was the god of battle among the Irish pagans, Nemon was his wife. The euhemerising tendency comes out strongly in Cormac's account of Manannán, a kind of Irish Proteus and Neptune combined, who according to him was "a renowned trader who dwelt in the Isle of Man, he was the best pilot in the West of Europe; through acquaintance with the sky he knew the quarter in which would be fair weather and foul weather, and when each of these two seasons would change. Hence the Scots and Britons called him a god of the sea. Thence, too, they said he was the sea's son—Mac Lir, i.e., son of the sea."
Another ancient Irish gloss[17] alludes to the mysterious Mór-rígan or war-goddess, of whom we shall hear more later on; and to Machæ, another war-goddess, "of whom is said Machæ's mast-feeding," meaning thereby, "the heads of men that have been slaughtered."
From all that we have said it clearly appears that carefully as the Christianised Irish strove to euhemerise their pantheon, they were unable to succeed. If, as Keating acknowledges, Brian, Iuchar, and Iucharba were gods, then à fortiori much more so must have been the more famous Lugh, who compassed their death, and the Dagda, and Angus Óg. Keating himself, in giving us a list of the famous Tuatha De Danann has probably given us also the names of a large number of primitive Celtic deities—not that these were at all confined to the De Danann tribes.