This book, while it deals primarily with civil conflicts between the Byzantine Emperor Basil II and the warrior-aristocrats Bardas Phocas and Bardas Sclerus, casts considerate light on Christian-Muslim relations in the Middle East during the century immediately preceding the crusades. These interactions-sometimes hostile, sometimes surprisingly intimate-occurred during that one period between the mid-tenth and mid-eleventh century when Shi"ite Islam, not Sunni Islam, dominated the Muslim world. The ethnic and secretarian fragmentation that marks present-day Islam was already well in place at the end of the tenth century.