It will be seen from this typical pedigree of the Mac Carthys--any other great family would have answered our purpose just as well--how families spring from clans and clans from septs--to use an English word--and septs from a common stem; and how the nearness or remoteness of some common ancestor bound a number of clans in nearer or remoter alliance to one another. Thus all septs of the great Eberian stem had some slight and faint tie of common ancestry connecting them, which comes out most strongly in their jealousy of the Eremonian or northern stem, but was not sufficient to produce a political alliance amongst themselves. Of a much stronger nature was the tie which bound those families descended from Eoghan Mór, the thirty-eighth ancestor from the first earl. These went under the name of the Eoghanachts, and held fairly together, always opposing the Dalcassians, descended from Cas. But when it came to the adoption of a surname, as it did in the eleventh century, those who descended from the ancestor who gave them their name, were bound to one another by the common ties or a nearer kinship and a common surname. It will be seen at a glance from the above pedigree, how, taking the Mac Carthys as a stem, and starting from the first earl, the Mac Finneens join that stem at the eleventh ancestor from the earl, the Mac Auliffes at the fifteenth, the O'Callaghans at the eighteenth, the O'Sullivans at the twenty-ninth, the O'Keefes at the thirty-second, the O'Dalys[7] of Munster at the thirty-second, the O'Donoghues, O'Mahonys, O'Mullanes, O'Cronins, O'Garvans, and Moriartys at the thirty-fourth, the O'Donovans, Collinses, O'Meehans, O'Hehirs, and Mac Davids at the thirty-sixth. Now each of these had his own genealogy equally carefully kept by his own ancestral bardic historian. If, for instance, the Mac Carthys could boast of nine kings of Munster amongst them, the O'Keefes could boast of ten; and an O'Keefe reckoning from Donal Óg, who was slain at the battle of Aughrim, would say that the Mac Carthys joined _his_ line at the thirty-sixth ancestor from Donal.