This book examines the career and publications of the French architect Julien-David Leroy (1724-1803) and his impact on architectural theory and pedagogy. Despite not leaving any built work, Leroy is a major international figure of eighteenth-century architectural theory and culture. Considering the place that Leroy occupied in various intellectual circles of the Enlightenment and Revolutionary period, this book examines the sources for his ideas about architectural history and theory and defines his impact on subsequent architectural thought. This book will be of key interest to graduate students and scholars of Enlightenment-era architectural history.