Medieval ideas of magic and the supernatural find their origins in the ancient world. They are widespread and interconnecting, a nebulous web that existed across classical, Germanic and Celtic cultures. The beliefs, practices and learning of the late Antique world, with its dialogue between pagan and Christian, shape later understandings of magic and the supernatural. This chapter focuses on classical and biblical contexts both as a way into medieval ideas, and as underpinning intellectual and literary traditions. Whereas many notions of magic and the supernatural in medieval England may find their origins in Germanic tradition, this is much less well evidenced than is classical belief and practice. Celtic belief survivals are even more difficult to trace. Beliefs and practices associated with magic and the supernatural in early European culture more generally are suggested almost exclusively through Latin writers, and their terminologies. Aspects of pagan ritual evidently survived in popular memory and culture, ingrained in folk belief and practice, but they were often interwoven with or overlaid by Christian ritual and also with inherited, learned ideas of magic and the supernatural from both classical and Christian tradition. Such notions may have been retained, in part, through folk practices of Roman Britons, interweaving with Germanic traditions brought by the Anglo-Saxons. Much less nebulous is the survival of analogous ideas in the classical writing inherited by the Middle Ages. Classical writing itself conveyed to later readers something of the diversity of notions of magic and the supernatural, popular and learned, positive and negative, in the Graeco-Roman world; it also gave to magic a detailed cultural history. The world order of gods, daimons or spirits, and natural correspondences was in many ways retained, in the concepts of the planetary gods and hierarchies of angels and demons. Crucial was the notion of a natural world encompassing a system of correspondences that might be understood, and their powers harnessed. Learned practices, especially astrology, but also ideas of encounter with the gods, maintained a powerful sway, as did the fearful attraction of those who comprehended and might control the forces of nature or the powers of daimons. Many of these ideas are also found in (and are sometimes in dialogue with) the Bible, but here magic functions within a more polarised moral scheme of good and evil, repeatedly repudiated by the rightful followers of Yahweh and Jesus.