This is a complete study of the works of the Irish playwright, travel writer, and poet J. M. Synge (1871–1909). A key and controversial figure in the Irish Literary Revival, and specifically in the Abbey Theatre, Synge’s career was short but dynamic. Moving from an early Romanticism, through Decadence, and on to a combative, protesting modernism, the development of Synge’s drama was propelled by his contentious relationship with the Irish politics of his time. This book is a full and timely reappraisal of Synge’s works, exploring both the prose and the drama through an in-depth study of Synge’s archive. Rather than looking at Synge’s work in relation to any distinct subject, this study examines Synge’s aesthetic and philosophical values, and charts the challenges posed to them as the impetus behind his reluctant movement into a more modernist mode of writing. Along the way, the book sheds new and often surprising light on Synge’s interests in occultism, pantheism, socialism, Darwinism, modernization, and even his late satirical engagement with eugenics. One of its key innovations is the use of Synge’s diaries, letters, and notebooks to trace his reading and to map the influences buried in his work, calling for them to be read afresh. Not only does this book reconsider each of Synge’s major works, along with many unfinished or archival pieces, it also explores the contested relationship between Revivalism and modernism, modernism and politics, and modernism and Romanticism.