Relations between Christians and Muslims and vice versa are the focus of significant contemporary interest, both in the political arena and the community at large. In the Iberian Peninsula during the Middle Ages, Christianity and Islam co-existed side by side throughout many centuries as the official religions of Muslim al-Andalus on the one hand, and the Christian kingdoms in the north of the peninsula on the other.Following the publication of a series of articles, this is his first full-length treatment of the subject to examine what being a non-Muslim meant in al-Andalus, both in the higher echelons of society and at a humbler level. Mozarabism in Leon and Toledo are considered at length, with chapters exploring the issues that arose when Mozarabs were relocated in twelfth-century Aragon, and in sixteenth-century Toledo - a pivotal point in their efforts to retain their identity.