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.
Nodens (Cthulhu Mythos)
Lovecraft may have based Nodens on Arthur Machen's "The Great God Pan" (1890) because Machen was one of Lovecraft's favorite authors. In the novel, Machen describes a late Roman inscription hinting that Nodens is actually the titular god Pan.
On one side of the pillar was an inscription, of which I took a note. Some of the letters had been defaced, but I do not think there can be any doubt as to those which I supply. The inscription reads as follows: