Runciman examines the revival of the Frankish kingdom at the time of the Third Crusade until its collapse a century later. The various themes of the book include: Christiandom, the replacement of the cultured Ayubites by the less sympathetic Mameluks as leader of the Muslem world, and the coming of the Mongols. He includes a chapter on architecture and the arts, and an epilogue on the last manifestations of the Crusading spirit.