Richard Sharpe Shaver
Richard Sharpe Shaver achieved notoriety in the years following World War II as the author of controversial stories which were printed in science fiction magazines wherein Shaver claimed that he had personal experience of a sinister, ancient civilization that lived in caverns under the earth. The controversy stemmed from the fact that Shaver and his editor/publisher Ray Palmer claimed Shaver's writings, while presented in the guise of fiction, were fundamentally true.