The literatures of medieval Wales and Ireland are among the richest vernacular traditions of medieval Europe. From a large corpus of poetry and prose, key texts such as the Welsh Mabinogion, the Irish sagas, Celtic Latin literature, chronicles, saints' lives and court poetry have established their place within the written legacy of medieval Europe. This collection of original essays by leading Celtic scholars, writing in honour of Catherine McKenna, Professor of Celtic at Harvard University, goes beyond the familiar canon of medieval Celtic literatures to showcase a wide range of Welsh and Irish texts that are compelling in their literary imagination and technical innovation.