The Byzantine Empire originated in AD 395 from the definitive subdivision of the Roman Empire into two distinct political entities: the Western Empire and the Eastern Empire. While the Western Empire disappeared in 476, due to Germanic invasions, the Eastern Empire endured for centuries. During Justinian’s reign (527-565) a good portion of the western territories were reconquered for a time and the Empire retained a distinctive ‘Roman’ nature at least until the reign of Heraclius (610-641). But during his reign, the Eastern Empire came under attack from the expanding Muslim Arabs, losing a much of its original Eastern territories. With Imperial power weakened and restricted largely to the Balkans and Anatolia, the ‘Roman’ nature of the Eastern Empire became progressively more Greek and transformed into what we know as ‘the Byzantine Empire’ (though they called themselves Romans to the end). Despite being surrounded by enemies, the Byzantines defended their remaining domains for a further half a millenium, their territories expanding and contracting with fluctuating fortunes. This tenacious survival was largely due to the ability of their military to adapt (as Roman armies always had) to emerging threats from a wide variety of enemies. The Byzantine Empire collapsed only in 1204, when attacked by forces of the Fourth Crusade, its ostensible allies. In addition to presenting an overview and analysis of the various campaigns of the period, Gabriele Esposito provides a complete review of Byzantine military organization, weapons, tactics and equipment. The clear text is lavishly illustrated with dozen of colour photographs of replica arms, armour and costume in use.