By Uncle Bob’s AI and JM Cozzoli
Cults, hereditary orders, and esoteric sects run through Lovecraft’s oeuvre. These organizations (groups) are the human side, mostly, of the Mythos: ordinary people, questionable people, and those that are not quite people, who have gladly or dangerously made contact with the Great Old Ones and the Outer Gods, while awaiting, summoning, or trying to hobnob with them. This incomplete but important primer lists the principal groups in Lovecraft’s own writing, then broadens to later authors who borrowed, extended, and tricked them out into the growing Cthulhu Mythos. References are cited at the end.
In Lovecraft’s Own Writing
The Cult of Cthulhu The Call of Cthulhu (1928)
A diffuse, worldwide secret cult that worships the Great Old Ones and awaits the day “when the stars are right” and Cthulhu rises from sunken R’lyeh. Lovecraft shows it through degenerate swamp worshippers in the Louisiana bayous and the Esquimaux diabolists of Greenland, with others alluded to in New Zealand and beyond, united by the chant “Ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn.” The captured cultist Old Castro supplies its doctrine. The story was first published in Weird Tales in February 1928, and this cult is the template for nearly every Mythos cult that follows.
The Esoteric Order of Dagon The Shadow over Innsmouth (1936)
A hereditary religious order founded by Captain Obed Marsh in the decayed Massachusetts port of Innsmouth, where it displaced the town’s Christian churches after Marsh returned from the South Seas around 1838. Members worship Dagon, Mother Hydra, and (to a lesser degree) Cthulhu, and interbreed with the amphibious Deep Ones in exchange for gold and bountiful fishing. Written in 1931 and first published in 1936, it is Lovecraft’s most realized cult, most alluded to by later writers.
The Church of Starry Wisdom The Haunter of the Dark (1936)
A Providence sect founded around 1844 by Professor Enoch Bowen, an archaeologist and occultist, which used the Shining Trapezohedron to summon and commune with an avatar of Nyarlathotep, the “Haunter” of the title. Public outcry and a string of disappearances eventually shut it down. Lovecraft wrote the story for his correspondent Robert Bloch as part of a friendly exchange of tales, and the church has had a long afterlife in other hands.
The Witch-Cult of Keziah Mason The Dreams in the Witch House (1933)
The lineage of Keziah Mason, a Salem witch who vanished from captivity in 1692 and used non-Euclidean geometry to slip between dimensions. She is served by the rat-like familiar Brown Jenkin and ultimately by the Black Man — Nyarlathotep in human guise — having signed the Book of Azathoth. First published in the July 1933 Weird Tales, the story fuses period witch-cult lore with Mythos cosmology.
The Red Hook Cult The Horror at Red Hook (1927)
A syncretic immigrant cult in Brooklyn led by the wealthy scholar Robert Suydam, worshipping Lilith and pre-human powers through Kabbalistic and Near-Eastern ritual. More occult-criminal than cosmic, it is an early sketch of the esoteric group idea Lovecraft would later perfect.
The Kingsport Yule Cult The Festival (1925)
A hereditary New England family cult that performs an ancient subterranean Yuletide rite beneath the old town of Kingsport. Less a formal organization than an inherited tradition of worship passed down through bloodlines. Leave it to Lovecraft to dampen the Christmas spirit.
Human Servitors of the Mi-Go The Whisperer in Darkness (1931)
Not a named body, but a network of human agents who do the bidding of the Mi-Go (the Fungi from Yuggoth) in the Vermont hills, helping conceal the aliens’ presence and their practice of removing human brains into cylinders for transport between worlds.
Expansion by Later Authors (a work in progress)
The Cthulhu Mythos was greatly broadened after Lovecraft’s death. The term was originally coined by August Derleth. As Lovecraft’s own devotees pooled his original gods, esoteric books and groups, and cosmic frailties, they created a fictional cosmology that continues to grow within the Lovecraftian universe.
August Derleth systematized Lovecraft’s writings into a scheme of warring elemental gods. One can blame Derleth for inserting the concept of good vs evil into Lovecraft’s nihilistic and indifferent universe. But you can also argue that his addition to the Cthulhu Mythos provides emotional frameworks that were missing in Lovecraft’s original stories, making his otherwise nihilistic lore highly marketable, emotionally relevant, and easier to commercialize for modern audiences (especially in regard to movies and games).
He kept the Innsmouth and Marsh-family material and Deep One worship alive across his Trail of Cthulhu stories, using Lovecraft’s framework as a recurring backdrop. The stories originally ran in Weird Tales between 1944 and 1952.
Robert Block invented his own forbidden grimoire, De Vermis Mysteriis by the wizard Ludvig Prinn, and populated stories like The Shambler from the Stars with sorcerers and cultists. The Church of Starry Wisdom that Lovecraft built into The Haunter of the Dark grew out of this back-and-forth, and has since been adopted by many later writers as a continuing organization.
Robert E. Howard
Robert E. Howard, creator of Conan the Barbarian, Contributed Nameless Cults (von Junzt’s Unaussprechlichen Kulten), a forbidden book that catalogues precisely these kinds of secret worshippers, and depicted active cults in The Black Stone, first published in the November 1931 issue of Weird Tales.
Clark Ashton Smith
Clark Ashton Smith provided the priesthood and cult of Tsathoggua, the toad-god, in his Hyperborean tales, a series of dark fantasy and cosmic horror stories set on the fictional, prehistoric northern continent of Hyperborea. Lovecraft then referenced Smith’s addition in his own work. Smith’s Hyperborea stories were published in Weird Tales between 1931 and 1958. “The tales frequently feature the legendary continent’s inhabitants, such as the thieves Satampra Zeiros and Tirouv Ompallios, or the doomed wizard Eibon.” (quote from HorrorBabble on Youtube).
Ramsey Campbell
At the suggestion of Arkham House publisher August Derleth, Campbell transplanted his early Lovecraft-inspired stories from New England to the Severn Valley in England, inventing towns like Brichester, Camside, and Temphill, and created new cults and servitor-followers, most famously the worshippers of the lake-dwelling god Gla’aki, whose teachings fill the Revelations of Gla’aki, introduced in The Inhabitant of the Lake (1964). Instead of solely relying on traditional Lovecraftian gods, Campbell created his own pantheon of horrors: Gla’aki, a green, slug-like Great Old One covered in eyes who lives in a local lake, along with the dread entity Daoloth and the insectoid Insects from Shaggai. For fans of his cosmic horror, Campbell’s Lovecraftian works are comprehensively collected and expanded in his book Cold Print, which traces his evolution from direct Lovecraft imitation to his own uniquely chilling voice.
Brian Lumley
Brian Lumley, while using the Lovecraftian framework, created the Wilmarth Foundation, a secret organization that fights the Cthulhu cult, named for the narrator of The Whisperer in Darkness. It debuts in his novel The Burrowers Beneath (1974), first in the Titus Crow series, which turns the struggle into open occult warfare, bringing Derleth’s good vs cosmic evil trope into the spotlight.
Lin Carter
Lin Carter expanded the universe with additional cults, gods, and forbidden books in an effort to expand and systematize the Mythos. Through his work and the Call of Cthulhu tabletop role-playing game, the Esoteric Order of Dagon in particular became one of the most reused elements in all of later Mythos fiction. Carter developed his own distinct series of mythos stories centered around the lost continent of Mu and the deep Pacific (Xothic Legend Cycle). This cycle introduced new Great Old Ones (such as Ythogtha and Zoth–Ommog), fictional lore tomes (the Zanthu Tablets and Ponape Scripture), and the Sanbourne Institute of Pacific Antiquities as a counterpart to Lovecraft’s Miskatonic University. In 1972, he published the seminal non-fiction study Lovecraft: A Look Behind the Cthulhu Mythos. This book served as a history of the “Lovecraft Circle” and attempted to map out a definitive canon of mythos stories, heavily influencing future roleplaying games and anthologies. Carter also adhered to Derleth’s alteration of Lovecraft’s original nihilism, turning the universe into one of good vs evil, which, by the way, is more commercial for role playing games (just saying). He also worked to connect all of the Lovecraftian gods and monsters into a unified and organized pantheon.
The descriptions above derive from the stories themselves, Wikipedia, the Lovecraft Wiki, Lovecraft Fandom, Reddit, and Youtube.