In April 2015, Pope Francis named the Armenian poet and theologian St. Gregory of Narek (c. 945–1003) a Doctor of the Church. Though venerated for centuries by Catholic and Orthodox Armenians, Gregory is an obscure figure virtually unknown to the rest of the Church. Adding to the extraordinary nature of the pope’s declaration, Gregory has the distinction of being the only Catholic Doctor who lived his entire life outside the visible communion of the Catholic Church. The Doctor of Mercy aims to provide an accessible introduction to Gregory’s literary works, theology, and spirituality, as well as to make the case for the contemporary relevance of his writings to the problems that face the Church and the world today.