The volume surveys the literary heritage and historical background of the Celtic peoples, tracing their arrival in Europe, linguistic position, and survival in manuscripts. It profiles early Christian writers and translator-scholars, examining St. Patrick’s writings, the literary activity around St. Columba and Iona, and Adamnan’s Vita Columbae, and studies key manuscripts such as the Book of Deer and other Gaelic and Latin codices. Chapters address linguistic discoveries, ogham inscriptions, the interplay of oral and written traditions, monastic centers of learning, and the recent revival of scholarly interest, while providing bibliographic guidance for readers and students seeking primary sources and modern studies.