A major new history of one of the greatest and most epic mysteries: the strange death of the Roman Empire. For half a millenium the empire of Rome stretched from Hadrian's Wall to the river Euphrates, a massive fortified state founded on military might and the pilllars of civilization - writting, the city, and the rule of law. But beyond these frontiers lay other lands, the lands of seemingly anarchic warrior tribes, the land of the Barbarians. The opening scenes of Gladiator are based on the victories of Marcus Aurelius over one such tribe, the Marcommani. Two hundered years later the Romans still seemed invincible, routing 30,000 Alamanii at the battle of Strasbourg. However, within a generation, the foundations of this order were shaken to their core, and Roman armies, as one contemporary put it, vanished like shadows. What had happened?