Thomas Glick presents a comparative history of the Islamic and Christian areas of Spain in the period between A.D. 711 and 1250 when these areas emerged as distinct political, social, and cultural entities. The author accounts for the social, political, and ethnic structures that developed between the frontiers of Muslim and Christian territories and explores the cross-cultural relationships and the transmission of ideas and techniques, mainly from the Islamic culture to the Christian culture in Spain. Glick argues that science and technology are key indicators of cultural influence. The author has revised this text considerably since the first edition appeared in 1979 to reflect the fruits of the increased exploration of Spanish medieval history spurred by the “historiographical revolution” in Spain over the last two decades.