the pedigrees and etymologies of names, that is, he has the pedigrees of the men of Erinn with certainty, and the branching off of their various relationships.’  Lastly, ’here are the four divisions of the knowledge of poetry (or philosophy),’ says the tract I have referred to; ’genealogies, synchronisms, and the reciting of (historic) tales form the first division; knowledge of the seven kinds of verse, and how to measure them by letters and syllables, form another of them; judgment of the seven kinds of poetry, another of them; lastly, Dichedal [or improvisation], that is, to contemplate and recite the verses without ever thinking of them before.’"[75]

The pedigrees were collected and written into a single book, called the Cin or Book of Drom Snechta, by the son of Duach Galach, King of Connacht, an Ollamh in history and genealogies, &c., shortly before[76] the arrival of St. Patrick in Ireland, which happened about A.D. 432.  It is obvious, therefore, that these genealogies must have existed for centuries prior to this period.  Even if they were then committed to writing for the first time, they could have been handed down for many centuries orally by the Ollamhs; for no amount of literary effort could be supposed too great for a class of men so exclusively and laboriously devoted to learning.

As the Milesians were the last of the ancient colonists, and had subdued the races previously existing in Ireland, only their genealogies, with a few exceptions, have been preserved.  The genealogical tree begins, therefore, with the brothers Eber and Eremon, the two surviving leaders of the expedition, whose ancestors are traced back to Magog, the son of Japhet.  The great southern chieftains, such as the MacCarthys and O’Briens, claim descent from Eber; the northern families of O’Connor, O’Donnell, and O’Neill, claim Eremon as their head.  There are also other families claiming descent from Emer, the son of Ir, brother to Eber and Eremon; as also from their cousin Lugaidh, the son of Ith.  From four sources the principal Celtic families of Ireland have sprung; and though they do not quite trace up the line to

    “The grand old gardener and his wife,”

they have a pedigree which cannot be gainsaid, and which might be claimed with pride by many a monarch.  MacFirbis’ Book of Genealogies,[77] compiled in the year 1650, from lost records, is the most perfect work of this kind extant.  But there are tracts in the Book of Leinster (compiled A.D. 1130), and in the Book of Ballymote (compiled A.D. 1391), which are of the highest authority.  O’Curry is of opinion, that those in the Book of Leinster were copied from the Saltair of Cashel and other contemporaneous works.