Arthur Machen
Around 1890 Machen began to publish in literary magazines, writing stories influenced by the works of Robert Louis Stevenson, some of which used gothic or fantastic themes. This led to his first major success, "The Great God Pan". It was published in 1894 by John Lane in the noted Keynotes Series, which was part of the growing aesthetic movement of the time. Machen's story was widely denounced for its sexual and horrific content and consequently sold well, going into a second edition.
The Dunwich Horror
Lovecraft's main literary sources for "The Dunwich Horror" are the stories of Welsh horror writer Arthur Machen, particularly "The Great God Pan" (which is mentioned in the text of "The Dunwich Horror") and "The Novel of the Black Seal". Both Machen stories concern individuals whose death throes reveal them to be only half-human in their parentage. According to Robert M. Price, "'The Dunwich Horror' is in every sense an homage to Machen and even a pastiche. There is little in Lovecraft's story that does not come directly out of Machen's fiction."