Merlin, the prophet and magus, is historically the second-best-known character from medieval literature, barely outstripped by his liege lord King Arthur. Beyond literature, he has entered our public consciousness to an even greater extent than Arthur, through the association of his name with all kinds of technological devices and commodities, many of them not in the least Arthurian. Most people know that Merlin is the epicenter of the supernatural in the Arthurian legend, his secularized male magic counterpoised by the female magic of Morgan le Fay and the Lady of the Lake and by the mystical religious miracle of the Holy Grail. Like theirs, his marvels are deeply rooted in pre-Christian traditions and molded by the Christian faith. The most famous stories about Merlin are tied to the matter of Arthurian Britain: his own miraculous birth foreshadows that of Arthur, which he arranges; his prophecies to King Vortigern announce the destinies of Arthur and the Britons; the building of Stonehenge creates a lasting monument to the ancient British; his training and advising of the young king-including the sword in the stone and the finding of Excalibur-establish the qualities of Arthur’s rule; his own doomed love affair reflects the erotic susceptibilities that undermine and finally ruin the society of Camelot; and his uncertain end leaves him, like Arthur, poised outside of history for return or rebirth, quondam et futurus.