Charles O’Conor of Ballinagare (1710–91) was one of 18th-century Ireland’s greatest scholars. Writing in both Irish and English, his work was clearly influenced by the Enlightenment and he regularly corresponded with the important intellectual and cultural figures of his day. O’Conor is regarded as having played a key role in founding the modern study of Ireland’s language, culture and history. He was author of the highly influential Dissertations on the ancient history of Ireland, along with many other works. He endeavoured to advance the civil rights of Roman Catholics, then marginalized by the Penal Laws, and in 1756 he was one of the founder members of the Catholic Association. This volume on the life and work of this great Irishman consists of a dozen essays by experts in language, literature, archaeology, history and architecture.