“The more reliable text-books and hand-books will be published, the greater will be the numbers of those taking up Celtic studies. As the fields of other more ancient and more recognised studies become exhausted, there will come a rush of students on to the fresh, and often, almost virgin soil of Celtic research, to study the great Celtic civilisation at its source, to collect the last lingering remnants of a mighty tradition. “Again and again it has happened during recent years that workers in other subjects have in their researches finally been led on to the Celtic soil, where lie the roots of much medieval lore, of many institutions, of important phases of thought. “And another thing, too, I will foretell. The re-discovery, as it were, of ancient Celtic literature will not only arouse abroad a greater interest in the Celtic nations, but it will lead to beneficial results among those nations themselves.” Mr. W. B. Yeats, in the _Treasury of Irish Poetry_, 1900, gives pen to similar reflections and anticipations:— “Modern poetry,” he writes, “grows weary of using over and over again the personages and stories and metaphors that have come to us through Greece and Rome, or from Wales and Brittany through the Middle Ages, and has found new life in the Norse and German legends. The Irish legends in popular tradition and in old Gaelic literature are more numerous and as beautiful, and alone among great European legends have the beauty and wonder of altogether new things. May one not say then, without saying anything improbable, that they will have a predominant influence in the coming century, and that their influence will pass through many countries.” The interest thus lately evolved in the literature of the Celts, who were among the earliest inhabitants of the country, and whose blood still courses in our British veins, has naturally awakened a desire in many minds to know the nature and extent of the literary legacy they have bequeathed—its substance and quality, and also to gain some acquaintance with the opinions and results of recent scholarship on the subject. But, strange to say, notwithstanding the activity of Celticists, no book has yet appeared which professes to give in short compass a general survey of the whole field. There is thus, I venture to think, room for such a volume as the present, which is intended to serve as a popular introduction to the study of the literature. Containing, as it does, the gist of two series of lectures which I delivered under the Maccallum Bequest in the University of Glasgow during the sessions 1900–1 and 1901–2, it is now prepared and issued with a view to meeting the demands not only of the general reader, but also of the private student in quest of a guide to the original sources, the authorities, and books on the subject.