"[1] The essay sets out in detail the major events of Howard's fictional prehistory, both period before and after the time of the Conan stories.
An unnamed Howard fragment published by Glenn Lord[3] features two grave robbers, Allison and Brill, who discover in the Egyptian desert a structure older and different from anything they encountered before.
Brill's source for the information is the Unaussprechliche Kulte (also known as Nameless Cults), a fictional work of Cthulhu Mythos arcane literature, cited in other Howard stories.
Howard's story "Men of the Shadows" includes a long historical narrative, similar in style to "The Hyborian Age" but different in detail.
The Hour of the Dragon, the only Conan novel authored by Howard, expands upon the history of the world presented in this essay by introducing a new ancient empire called Acheron that had ruled the Hyborian kingdoms in the past.