'God wills it!' With that cry of medieval knights a new era in European history began. Across Europe a wave of pious enthusiasm led many thousands to leave their homes, family, and friends to march to a distant land in a great struggle for Christ. Yet the crusades were more than simply a holy war. They represent a synthesis of attitudes and values that were uniquely medieval—so medieval, in fact, that the crusading movement is rarely understood today. This book places the crusades within the medieval social, economic, religious, and intellectual environments that gave birth to the movement and nurtured it for centuries. The events of the crusades to Palestine and Europe's periphery are narrated in a clear, concise, and compelling manner. Special attention is also given to the crusades' effects on the Islamic world and the Christian Byzantine East. Also included is a historiographical overview of the subject as well as an up-to-date select biography.