If you're looking to develop a Holmes campaign setting, probably one of the best places to start, other than with the "quirks" in the rules themselves which offer a wealth of material, is with the author's Boinger and Zereth stories. I've just finished reading his book The Maze of Peril (which can still be purchased from the publisher), as well as the three short stories in the early Dragon magazine (31, 46 & 58). I know he published some more in Alarums & Excursions, but I haven't seen those.

These stories paint a great picture of Holmes' view of his gaming world:


Quote:

Somewhere beneath the surface of this ancient land the tunnels and corridors of some prehistoric race coiled and raveled, delved and probed unimaginable depths into the core of the world. Corridors of wealth, they were also tunnels of deadly peril, for many of the rash adventurers who set forth for the secret entrances to the fabled Underworld were never heard from again.What race or races had built the original maze no one knew. It seemed, in the opinion of the sages and magicians of the time, that there must have been many layers of dungeons and underworlds laid down, one atop the other, as the world crust was formed, so that now no one knew, or even guessed, how many levels it extended below the surface.

Above ground, Boinger the halfling comes from "the Meadow Country to the south", his mate Bardan the Dwarf from "the Cold Mountains", and Zereth the "dark elf" is of the Elidel, the Old People. The novel starts in the town of Caladan, in the land of Labolinn. Other lands include Amazonia "a great island kingdom", pirate isles to the south of that, and the "island citadel of the Frog-Heads and the Fish-Heads, the worshippers of Dagon" to the north.

Races are quite diverse and freely mix, with humans, demi-humans, centaurs, serpentmen, satyrs and things with antennae all drinking together in the town's taverns.

There is also a strange mixture of the real-world and fantasy. The elves follow the pagan "Goddess" and are are attuned to the moon, whereas human religion is Christianity, complete with crosses and Latin prayers.

There is probably enough information in these stories to build a skeleton of a Holmes world.

OK, here's some more elements from his Boinger stories and his 1980 Psychology Today article Confessions of a Dungeon Master:

Places: The Enchanted Forest, Southern Jungle, Desert of Irem, slave market at Mar'koosh, old Suloise city buried under Witch's Hill outside the town of Caladan. The coast is barely 100 leagues east of Caladan.

Gods & Demons: Khalk'ru the Dissolver, Ozymandias, the Mi-Go, the Fungi from Yuggoth, Artaban, Asmodeus, Mithra (used a lot), Hastur, Cthulhu, Azathoth, (Church of) Saint Mellon, Gor, Thor, Odin, Crom, Hypnos, Morpheus and Ishtar.

Races & Classes: Gnome, Samurai, Viking, Naga, Gremlin, Angels, Lilliputians, "black sons of Elendil". Paladins are Knights of the Cross and take vows of chastity and purity.

More on the Amazons: The Amazons are a sea-faring nation, with the Queen's Navy consisting of a fleet of purple and red-sailed longships, armed with catapults and "Greek Fire". The Queen's Own Cavalry are virginal warrior maidens who ride unicorns. Amazon archers remove one breast. Their men are considered "effeminate" if they pursue non-domestic roles. The Queen consults "the Oracle" and as a nation, they worship "the Goddess". The frog-men have been disrupting the shipping lanes between Amazonia and the mainland.

More on the Dagonites: Worshippers of Dagon consist of two races, bronze armed and armoured humanoid frog-men and Weresharks. One of their "places of power" is a temple to Dagon, the evil sea god, which is a black pyramid located on an island, in an underground lake. The lake is connected to the coast by an underground river. Dagonite priests are toga-wearing frog-men, with fish headdresses. The arch priest wears a "mask-headdress of jade fins and scales" and carries "a tall staff, carved at the top into writhing tentacles", which operates like a Snake Staff, turning into a ten foot long purple octapoid creature.

Within the pyramid is a massive statue of Dagon, depicting him as "a tentacled being with a crested head and bulbous fish eyes, gaping shark fanged jaws, and an expression of utter malignity." "Huge plates of mother-of-pearl were his eyes; great overlapping sea shells covered his body like scales." The Dagonite priests can cast a collective spell, calling on Dagon to animate his statue in defence of the temple.

Literary Influences: Holmes said he included in his world, bits from A. Merritt's The Dwellers in the Mirage, Barsoom, Hyperborea, Edgar Rice Burroughs, Robert E. Howard, H. Rider Haggard, H.P. Lovecraft and Clark Ashton Smith.

Hope this is all helpful.