This collection explores the historical origins of our modern concepts of intellectual or learning disability. The essays, from some of the leading historians of ideas of intellectual disability, focus on British and European material from the Middle Ages to the late-nineteenth century and extend across legal, educational, literary, religious, philosophical and psychiatric histories. They investigate how precursor concepts and discourses were shaped by and interacted with their particular social, cultural and intellectual environments, eventually giving rise to contemporary ideas. The collection is essential reading for scholars interested in the history of intelligence, intellectual disability and related concepts, as well as in disability history generally.