Devout fans of H.P. Lovecraft are likely familiar with Arthur Machen. In Supernatural Horror in Literature, Lovecraft’s vast survey of the weird tale, raised in as perhaps the greatest living writer of the uncanny, in whose stories frightful horrors “attain an almost incomparable substance and realistic acuteness.” Machen’s The Great God Pan, about an overreaching scientist who makes contact with a blasphemous deity, is one of the most obvious influences on Lovecraft’s Cthulhu Mythos, but less well-known is the pervasive faerie lore that entered the American’s works through the Welshman’s writings. Machen’s works are fraught with faeries — not, of course, the sanitized figures of a Hans Christian Anderson story but (as Lovecraft terms them) but “dark primal beings of immemorial antiquity” who live on beneath the hills.

Machen, unlike Lovecraft, was not out to build a comprehensive mythos, and his stories do not present a unified portrait of the fae. In some stories, they are clearly supernatural, or at least partly so, while in others — like ‘The Novel of the Black Seal‘ — they seem to be wholly material, an ancient race-driven underground by long-ago invaders. That idea was neither Machen’s nor new. It had been popularised by (among others) Grant Allen, a Victorian science writer and an early adopter of Darwin’s theory of evolution. Allen suggested that the faeries of British folklore were mythologized memories of the Neolithic inhabitants of the isles, who were imagined to be smaller and darker and who vanished at the coming of the Celts. The newcomers imagined that their predecessors had hidden in the hill-forts and mounds they left behind, and such places were ever after cast as portals to the Otherworld. This faerie origin story held currency well into the 20th century; Walter Evans-Wentz cites recollections of “an ancient pygmy race” in his famous 1911 book The Fairy-Faith in Celtic Countries, and as late as 1932 scholars were asking in august journals like Folklore whether the Little People were “an Earlier Race of Men.”

The faeries of ‘The Black Seal’ and ‘Out of the Earth‘ are feral creatures, degenerated or unevolved from an ancient state of savagery. The idea of degeneration must have appealed to the virulently racist Lovecraft, who could proudly trace his descent from the Mayflower families and who was scandalised by the descendants of once-great families who now lived in rural poverty. ‘The Dunwich Horror‘ is as concerned with such genealogical slippage as it is with supernatural horror: the inhabitants of that cursed village, we are told, came mainly from old Salem stock — there’s even a Corey, doubtless from the family of Giles. By the tale’s opening, though, they’re an illiterate bunch who live in the tumbledown ruins of stately old homes and speak in comical rustic dialects.

Even Dunwich’s name points to deep antiquity. It means something like “hill village”, dun coming from the same root that gives us the modern dune: a fitting enough name for a hamlet clustered around huge and uncannily bare hills, within which awful things seem to live. But dun could also, in Old and Middle English, mean black, and that — along with the homonym wic for witch — points to the supernatural horror lurking under the town. For this Lovecraft owes a great deal to Machen’s ‘The White People‘, which shows a very different side to the fae. The narrator of ‘The White People‘ is a half-ignorant heir to ancient lore, who spends the tale wandering the hills and their arcane stone circles and communing with frightful Otherworldly figures, just like Lovecraft’s semi-human Wilbur Whately. Lovecraft’s debt is obvious in some ways — he lifts esoteric-sounding terms like “Aklo” and “voor” directly from the text, and Witches’ Sabbath of ‘The White People‘ is clearly reflected in the Whately family’s hilltop revels on Walpurgis Night. In others, it is more subtle, like the kinship between the two narrators and the way ‘The Dunwich Horror‘ seems to wish it were set in England, or perhaps Machen’s Wales. The hilltops of Dunwich are crowned with “great rings of rough-hewn stone columns” a common enough sight in Snowdonia, but not New England — and the “Indians” who performed dark orgiastic rites within those things seem a thin stand-in for the mythical pre-Celtic peoples.

Moreover, Lovecraft’s story is keyed directly to a “Celtic” ritual year. Subterranean fires and underground voices are heard on Halloween, the old wizard Whately dies on Lammas, and the horror of the story’s title erupts between Lammas and the equinox. Whately is born on “Candlemas, which people in Dunwich curiously observe under another name;” that name is not given but is probably Imbolc, midway between the solstice and the spring equinox. That would put his conception not far off from May Eve — Beltane — of the previous year. The lesser-known counterpart to Halloween, May Eve is a day of increased supernatural activity in British folklore and medieval literature: in the 12th or 13th century Lludd and Llevelys it’s the day on which a hellish scream echoes through the island, inducing miscarriages among women and rendering the land barren. In Wales, it was traditionally welcome in with bonfires, like the ones Wilbur and his mother light atop the hills of Dunwich each year as part of their dark worship of Yog-Sothoth.

Wilbur, probably conceived on May Eve, owes something to the folkloric figure of the changeling. He is unnaturally intelligent and even given slightly pointed ears, though he grows to a prodigious size where changelings usually remain shrunken. A changeling appears in ‘The Novel of the Black Seal‘; like Wilbur, it’s implied that he is the son of an otherworldly father and a mother who was caught wandering the haunted hills at night. Both figures are the scions of vanished fathers, inhuman things that dwell underground after retreating long ago from the upper world. But nothing in Machen’s stories or the folklore that inspired them suggests the possibility of a return: an apocalyptic emergence of those awful beings that will restore their sovereignty over the earth, and the very thing that Wilbur Whately seeks to bring about through black magic and old rites. Though thwarted in ‘The Dunwich Horror‘ by a group of enterprising academics, that black day — when the stars align and dead Cthulhu wakes — hangs over almost every one of Lovecraft’s stories, moving them away from Machen’s folklore to the cosmic significance of the Cthulhu mythos that has haunted horror fiction for nearly a century.