Even Sir G.C.Lewis admits that "commemorative festivals and other periodical observances, may, in certain cases, have served to perpetuate a true tradition of some national event."[70] And how much more surely would the memory of such events be perpetuated by a people, to whom they had brought important political revolutions, who are eminently tenacious of their traditions, and who have preserved the memory of them intact for centuries in local names and monumental sites! The sources from whence the first annalists, or writers of Irish history, may have compiled their narratives, would, therefore, be--1.

The Books of Genealogies and Pedigrees.2.

The Historic Tales.3.The Books of Laws.4.The Imaginative Tales and Poems.5.National Monuments, such as cromlechs and pillar stones, &c., which supplied the place of the brazen tablets of Roman history, the _libri lintei_,[71] or the chronological nail.[72] The Books of Genealogies and Pedigrees form a most important element in Irish pagan history.

For social and political reasons, the Irish Celt preserved his genealogical tree with scrupulous precision.

The rights of property and the governing power were transmitted with patriarchal exactitude on strict claims of primogeniture, which claims could only be refused under certain conditions defined by law.