This anonymously authored Middle English adaptation of the Old French Vulgate Cycle survives in one manuscript, Cambridge University Library MS Ff.3.11, and was written near the middle of the fifteenth century, making it the single earliest piece of prose Arthuriana in Middle English. A complete account of its titular character’s life, the Prose Merlin follows the sorcerer from birth to final imprisonment by his former apprentice, Nimiane. Although composed not long before Malory’s Arthurian epic Le Morte D’Arthur, the Prose Merlin provides a more focused and optimistic account of the Arthurian court, while also reveling in the supernatural themes of its subjects. This edition, accessible to the reader unfamiliar with Middle English prose, is the first complete edition of the romance published since the nineteenth century, making it a valuable resource for modern scholarship.