The late Byzantine period was a time characterized by both civil strife and foreign invasion, framed by two cataclysmic events: the fall of Constantinople to the western Europeans in 1204 and again to the Ottoman Turks in 1453. Mark C. Bartusis here opens an extraordinary window on the Byzantine Empire during its last centuries by providing the first comprehensive treatment of the dying empire's military. Although the Byzantine army was highly visible, it was increasingly ineffective in...