Early Irish History and Mythology. Dublin: D.I.A.S., 1946. First Edition. Pp x, 568. First Edition. Publisher’s black cloth boards, title in gilt to spine, in original dust jacket. A fine bright copy.

Regarded on publication as the most important book on Irish history since the publication of Eugene O’Curry’s ‘The Manuscript Materials of Ancient Irish History,’ in 1860. However, it was also fiercely debated. Contemporary scholars, while admiring O’Rahilly’s linguistic mastery, often took issue with his methods and conclusions:

Built upon an extraordinarily wide and detailed knowledge of early Irish literary sources, linguistic evidence, and classical authors like Ptolemy, whose geography of Ireland O’Rahilly subjected to rigorous analysis. Events and persons of early Christian Ireland are occasionally discussed; but for the most part it confines itself to the history of Ireland previous to official introduction of Christianity in A.D. 431.

O’Rahilly’s work was a culmination of a lifetime’s scholarship by one of Ireland’s leading Celticists, and it continues to be a vital reference point, even for those who disagree with its conclusions