The book was originally called "Nameless Cults" by Robert E. Howard in his stories "The Children of the Night" and "The Black Stone" published in "Weird Tales" in 1931. It is not clear whether the book is a complete invention by Howard, or if he based it on an enhancement of a real book. H. P. Lovecraft gave it a German title more in keeping with the German name of the fictional author, von Junzt, when he started using it in stories set in the Cthulhu Mythos. Not being a German speaker, Lovecraft asked his protege August Derleth for a translation. "Unaussprechlichen Kulten" was Derleth's suggestion. Derleth and others in the Lovecraft circle subsequently used both the book and the author in their stories.