Few periods defined medieval apocalypticism more than the waning of the Roman Empire in the West. For that reason, we start here with the fourth century AD rather than with Christ himself. The empire provided both a symbolic secular counterpoint to the Christian community, and a political body which it was prophesied had to fall before the End Times could begin. Sometimes the fate of the world already seemed inexorably bound to the successes and failures of the Roman world, and had for a long time, which meant that the profound crises which beset the Western Empire in the fourth and fifth centuries seemed to be of global importance. The migration and invasions of ‘barbarian’ groups, notably from the famous Gothic crossing of the Danube in 376 onwards, contributed to a destabilisation of political order and a cluster of anxieties about what it meant to be Roman and Christian. The cultural dissonance was pronounced. And when Rome itself was sacked in 410 by Alaric’s Goths and in 455 by Genseric’s Vandals, the cultural shock was muddied only a little by Alaric’s and Genseric’s adherence to a heretical form of Christianity and their pro-Roman ambitions. In the wake of such high drama, great patristic writers such as Augustine of Hippo and Jerome of Stridon began to set down strategies for understanding apocalyptic thought which responded to the changing worlds around them, while others saw nothing less than announcements of the approaching End itself. These were, in the words of one observer, the prophesied ‘perilous times’ (tempora periculosa [2 Tim. 3.1]).