This article presents a detailed new analysis of the conception, composition, publication, and immediate reception of John William Polidori’s influential story, ‘The Vampyre’ (1819), first attributed to Lord Byron. Polidori was instrumental in publishing the tale—and did so with a certain guile as part of a larger literary strategy. Yet he nevertheless fell victim to the duplicity of the publisher Henry Colburn. Polidori was consequently vilified by the Byron circle, which ultimately wrecked his career as a writer. What emerges from this close attention to publication is that the text is unlikely to have been written in 1816 at the Villa Diodati, alongside Frankenstein, but two and a half years later. This therefore challenges its significance as a supposed portrait of Byron, and allows Byron’s own contribution to vampire fiction (‘A Fragment’) to be re-evaluated. The paper also examines the pieces published alongside ‘The Vampyre’ on its first appearance, suggesting the likely authors of these supplementary texts.