The Mediterranean and its hinterlands were the scene of intensive and transformative contact between cultures in the Middle Ages. From the seventh to the seventeenth century, the three civilizations into which the region came to be divided geographically the Islamic Khalifate, the Byzantine Empire, and the Latin West were busily redefining themselves vis-a-vis one another. Interspersed throughout the region were communities of minorities, such as Christians in Muslim lands, Muslims in Christian lands, heterodoxical sects, pagans, and, of course, Jews. One of the most potent vectors of...