John William Polidori (1795-1821) was a British writer and physician. He is known for his associations with the Romantic movement and credited by some as the creator of the vampire genre of fantasy fiction.
In 1816, which became known as the Year Without a Summer, Polidori entered Lord Byron's service as his personal physician and accompanied him on a trip through Europe. At the Villa Diodati, a house Byron rented by Lake Geneva in Switzerland, the pair met with Mary Wollstonecraft Godwin, her husband-to-be, Percy Bysshe Shelley, and their companion (Mary's stepsister) Claire Clairmont.
One night in June after the company had read aloud from Fantasmagoriana, a French collection of German horror tales, Byron suggested they each write a ghost story. Percy Bysshe Shelley wrote A Fragment of a Ghost Story. Mary Shelley worked on a tale that would later evolve into Frankenstein. Byron wrote (and quickly abandoned) a fragment of a story, "A Fragment", featuring the main character Augustus Darvell, which Polidori used later as the basis for his own tale, The Vampyre, the first published modern vampire story in English.