Cthulhu Mythos
Cthulhu mythos is the term coined by the writer August Derleth to describe the shared themes, characters, and elements in the works of H.P. Lovecraft, his protegés, and writers influenced by him. Together, they form the mythos that authors, writing in the Lovecraftian milieu, have used—and continue to use—to craft their stories.[1]
Although this mythology is sometimes called the Lovecraft Mythos—most notably by the Lovecraft scholar S. T. Joshi[2]—it has long since moved beyond Lovecraft's original conception. Still, purists who wish to discuss Lovecraft's work, rather than the modifications and expansions of it written by others, consider this to be the most accurate term. Lovecraft himself occasionally referred to it as the Arkham cycle[3], after the main fictional town in his world, or Yog-Sothothery[4], after one of its primary gods.
Lovecraft and the mythos
In his essay "The Lovecraft Mythos", S. T. Joshi defines four key elements in Lovecraft's mythos: (1) the fundamental principle of cosmicism, (2) an imaginary New England setting, (3) recurring "pseudomythological" entities, and (4) works of arcane literature. Joshi points out, however, that Lovecraft never fully realized his mythos at any time in his career, but instead developed it gradually, adding elements to it with each story he wrote.[5]