(1893 — 1961)
He was a member of the Lovecraft circle, and his literary friendship with H. P. Lovecraft lasted from 1922 until Lovecraft's death in 1937. As part of the Lovecraft Circle, he was occasionally written into their stories as Klarkash-Ton.
Smith's short stories originally appeared in pulp magazines such as Weird Tales, Strange Tales, Astounding Stories, Stirring Science Stories, and Wonder Stories. He was considered to be the third member of the great triumvirate of Weird Tales, with Lovecraft and Robert Howard.
Many of Smith's stories were published in six hardcover volumes by Arkham House: Out of Space and Time (1942), Lost Worlds (1944), Genius Loci and Other Tales (1948), The Dark Chateau (1951), Spells and Philtres (1957), The Abominations of Yondo (1960), and Tales of Science and Sorcery (1964).
Smith occasionally used the pseudonyms of Carl Buxton, Benjamin De Casseres, and Timaeus Gaylord.
For more, see http://www.sf-encyclopedia.com/entry/smith_clark_ashton