This collection of studies examines the use of the written word in Celtic-speaking regions of Europe between c. 400 and c. 1500. Building on previous work as well as presenting the fruits of much new research, the book seeks to highlight the interest and importance of Celtic uses of literacy for the study of both medieval literacy generally and of the history and cultures of the Celtic countries in the Middle Ages. Among the topics discussed are the uses and significance of charter-writing, the interplay of oral and literate modes in the composition and transmission of medieval Irish and Welsh genealogies, prose narratives and poetry, the survival of Celtic culture in Brittany and of Gaelic literacy in eastern Scotland in the twelfth century, and pragmatic uses of literacy in later medieval Wales.