We have also for the same interpretation the authority of the annalist Tigernach, who, in his Annals of Ireland at the year 714, translates _Ui Eachach_ (now Iveagh, in the county Down), _nepotes Eochaidh_. On this subject it may not be uninteresting to the reader to hear the opinion of the learned Roderic O’Flaherty. Treating of the Hy Cormaic, a tribe located near Lough Foyle, in the present county of Londonderry, he says-- “_Hy_ or _I_ (which calls for an explanation) is the plural number from _Hua_ or _O_, a grandson, and is frequently prefixed to the names of progenitors of families, as well to particularize the families as the lands they possess, as _Dal_, _Siol_, _Clann_, _Kinel_, _Mac_, _Muintir_, _Teallach_, or any such name, pursuant to the adoptive power of custom.”--_Ogygia_, Part III. Chap. 76. Besides the words above enumerated, after which the names of progenitors are placed, there are others to be met with after which the names of territories are placed, as _Aes_, people; _Fir_ or _Feara_, men; _Aicme_, tribe; and _Pobul_, people; as _Aes Greine_, i.e., _the people of Grian_, a tribe located in the present county of Limerick; _Aes tri Magh_, _the people of the three plains_, in the same county; _Feara Muighe Feine_, _the men of Moy Feine_, now Fermoy, in the county of Cork; _Fir Rois_, _the men of Ross_, the name of a tribe in the present county of Monaghan; _Feara Arda_, i.e., _the men of Ard_, a tribe in the present county of Louth; _Pobul Droma_, in Tipperary. Many other names were formed by a mode not unlike the Latin and Greek method, that is, by adding certain terminations to the name or cognomen of the ancestors of the tribes. These terminations are generally _raighe_, _aighe_, _ne_, and _acht_, as _Caenraighe_, _Muscraighe_, _Dartraighe_, _Calraighe_, _Ciarraighe_, _Tradraighe_, _Greagraighe_, _Ernaidhe_, _Mairtine_, _Conmaicne_, _Olnegmacht_, _Connacht_, _Cianacht_, _Eoghanacht_, &c. &c. This is the usual form of the tribe names among the descendants of the Belgic families enumerated in the Books of Lecan and Glendalough, as existing in Ireland in the first century, and it is not improbable that the tribe names given on Ptolemy’s Map of Ireland are partly fanciful translations, and partly modifications of them. It appears from the authentic Irish annals, and the whole tenor of Irish history, that the Irish people were distinguished by tribe names _only_ up to the period of the monarch Brian Boru, who published an edict that the descendants of the heads of tribes and families then in power should take name from them, either from the fathers or grandfathers, and that these names should become hereditary and remain fixed for ever. To this period we must refer the origin of family names or surnames.