Explores medieval Irish interest in Classical mythology and historiography and how it could be situated within the framework of Christian salvation history. From allusions to the Olympians in seventh-century glosses to twelfth- and thirteenth-century vernacular adaptations of the epics of Vergil, Lucan, and Statius, Irish authors creatively re-imagined Greco-Roman mythology throughout the Middle Ages. They developed many strategies for situating the Classical deities within medieval Christian historiography, but rarely did they downplay or eliminate them. Some of these strategies, as this study reveals, reflected wider medieval European trends in Classical reception and mythography, whilst others were strikingly original and paralleled the ways in which Irish authors imagined the supernatural beings of their own pre-Christian past. This book examines why Irish authors were interested in the history and mythology of the ancient Mediterranean, and how Classical polytheism influenced their ideas about their own pagan past. It explores the ways in which depictions of Irish Otherworldly characters both shaped and were shaped by the gods and supernatural figures of the Classical adaptations. Based on close readings of texts such as the Irish version of Lucan, In Cath Catharda, this book argues that Classical scholarship in medieval Ireland was closely tied to medieval ideas about salvation history. Ultimately, it concludes that medieval Irish authors and audiences applied the same interpretive tools used for biblical exegesis to characters and events from Greco-Roman mythology, history, and literature, and to the supernatural inhabitants of pre-Christian Ireland alike.