In this book, Liz James offers a comprehensive history of wall mosaics produced in the European and Islamic middle ages. Taking into account a wide range of issues, including style and iconography, technique and material, and function and patronage, she examines mosaics within their historical context. She asks why the mosaic was such a popular medium and considers how mosaics work as historical 'documents' that tell us about attitudes and beliefs in the medieval world. The book is divided into two part. Part I explores the technical aspects of mosaics, including glass production, labour and materials, and costs. In Part II, James provides a chronological history of mosaics, charting the low and high points of mosaic art up until its abrupt end in the late middle ages. Written in a clear and engaging style, her book will serve as an essential resource for scholars and students of medieval mosaics.