This finely researched and written book began as a doctoral dissertation at Princeton University. Christian Sahner is associate professor of Islamic history at the University of Oxford and a fellow of Saint Cross College. His work is a boon to anyone interested in the interplay between Christians and Muslims as Islam expanded west in the seventh to the ninth centuries of the present era (ca. 660–860). It provides a description of the world in which the Christian martyrs (called “neomartyrs” by their contemporaries) lived and answers the question as to how the early medieval Middle East, northern Africa, and eventually Andalusia, progressively mutated from being a majority Christian territory into a majority Muslim society.