During the Middle Empire period (AD 180-284) the Roman army had to face the terrible 'Third Century Crisis', wherein a combination of socio-economic problems and new external threats threatened the Empire with complete collapse. Several provinces became temporarily independent from the central government of Rome, while others were frequently raided by foreign invaders. The Roman army had to fight with all its resources in order to reconquer a good portion of the Empire and preserve its unity. The Romans were forced to modernize and reform their forces to face the new challenges posed by a multitude of warlike enemies, such as the Persians in the Middle East or the Germanic Peoples in Central Europe. The previous military system based on the power of the legions' heavy infantry was completely revised, with the introduction of new organizational patterns. Cavalry became much more important than before, together with light troops specialized in skirmishing. The personal equipment of the Roman soldiers changed in a very significant way, with the introduction of new weapons that permitted the development of innovative tactics. Gabriele Esposito follows this evolution of Roman forces from the death of Marcus Aurelius to the rise of Diocletian, reconstructing the major military campaigns and explaining how the Roman military forces were transformed. All the major troop types are covered, with details on the organization and equipment of each contingent. The book is lavishly illustrated throughout with excellent colour photos of reconstructed costume and equipment in use. AUTHOR: Gabriele Esposito is an Italian researcher and a long-time student of military history, whose interests and expertise range widely over various periods. Most of his recent studies have been dedicated to the reconstruction of the organization, functioning and tactics of the armies across history; in each of his publications there is always some relevant space dedicated to the 'material culture'of the various armies taken into account and - more in particular - to the empirical science known as 'uniformology'. Gabriele is the author of numerous books on armies and uniforms and is a regular contributor to many specialized magazines in Italy, France, Netherlands and UK. His many previous works include Armies of Early Colonial North America 1607-1713; Armies of the Late Roman Empire 284-476; Armies of the Hellenistic States 323 BC to AD30; Armies of Celtic Europe 700 BC-AD 106; Armies of Ancient Greece, circa 500 BC to 338 BC; and The Macedonian Army of Philip II and Alexander the Great 359-323 BC, all published by Pen & Sword since 2018. He lives in southern Italy, near the ancient battlefield of Beneventum. 130 colour illustrations