In dealing with Irish proper names I have experienced the same difficulty as every one else who undertakes to treat of Irish history. Some native names, especially those with "mortified" or aspirated letters, look so unpronounceable as to prove highly disconcerting to an English reader. The system I have followed is to leave the Irish orthography untouched, but in cases where the true pronunciation differed appreciably from the sound which an English reader would give the letters, I have added a phonetic rendering of the Irish form in brackets, as "Muighmheadhon [Mwee-va-on], Lughaidh [Lewy]." There are a few names such as Ossian, Mève, Donough, Murrough and others, which have been almost adopted into English, and these forms I have generally retained--perhaps wrongly--but my desire has been to throw no unnecessary impediments in the way of an English reader; I have always given the true Irish form at least once. Where the word "mac" is not part of a proper name, but really means "son of" as in Finn mac Cúmhail, I have printed it with a small "m"; and in such names as "Cormac mac Art" I have usually not inflected the last word, but have written "Art" not "Airt," so as to avoid as far as possible confusing the English reader. I very much regret that I have found it impossible, owing to the brief space of time between printing and publication, to submit the following chapters to any of my friends for their advice and criticism. I beg, however, to here express my best thanks to my friend Father Edmund Hogan, S.J., for the numerous memoranda which he was kind enough to give me towards the last chapter of this book, that on the history of Irish as a spoken language, and also to express my regret that the valuable critical edition of the Book of Hymns by Dr. Atkinson and Dr. Bernard, M. Bertrand's "Religion Gauloise," and Miss Hull's interesting volume on "Cuchullin Saga," which should be read in connection with my chapters on the Red Branch cycle, appeared too late for me to make use of. RÁTH-TREAGH, OIDHCHE SAMHNA MDCCCXCIX. CONTENTS