In late antiquity, demons dwelled in the empty places on the outskirts of the Christian imagination, especially in the vastness of the desert. There they confronted an ever-increasing influx of hermits and other “athletes of God” who invaded their domain in pursuit of solitude and an escape from the social obligations of urban life. Some authors in this period thought about demons abstractly as personifications of the sins that diverted monks from their holy purpose, like the so-called noonday demon who caused listlessness and distraction. For others, however, these agents of the Devil were real threats to solitary monks. Visiting their remote cells by night, demons not only appeared in alluring forms to arouse their passions but also struggled physically with the saints in ways that left them bruised and bleeding in the morning. As the literature of the desert spread to western Europe, so too did the range of demonic activity. From the sixth century onward, demons appeared increasingly outside of their desert habitat, but their power was diminished. While dangerous to ordinary people, they were depicted as paper tigers easily vanquished by the saints. They remained formidable adversaries in the otherworld, however. In the early Middle Ages, stories about visions experienced by monks on the verge of death portrayed demons as predatory in their pursuit of sinful souls, which they snatched greedily from the helping hands of angels and carried off to the depths of Hell.