The Newberry Library in Chicago possesses one of the most distinguished collections of medieval and Renaissance manuscript books in North America. Based on two major private collections of the late nineteenth century—those of Henry Probasco and Edward E. Ayer—and scrupulously added to in this century, the holdings include late medieval bibles and breviaries, books of hours and books of homilies, and seminal texts on astronomy. Some of the books, such as those from the libraries of Philip the Good and Anne of Brittany, are beautifully illuminated. But the collection also includes an unusual array of "typical" medieval books, chosen not for their beauty but for their paleographical, codicological, and textual interest. Such codices include an eleventh-century Carthusian monk, and numerous books of hours adapted for feminine use. Paul Saenger has painstakingly identified the text, illumination, physical structure, and provenance for each of the more than 200 books in the collection to provide an exemplary guide to literate culture in the late Middle Ages. This catalogue, carefully researched and handsomely illustrated, will be an invaluable resource for historians, art historians, paleographers, bibliographers, and collectors.