Two very early uses of the term “the Lovecraft mythos”. The first leaves it open — was Robert Anton Wilson actually talking about the Derleth mythos or the original Lovecraft Mythos? We may never know, unless someone can dig up an interview which touches on the topic. The second use is from the critic Jeffrey P. Miller, and is very clear-cut.

1977: Robert Anton Wilson, Cosmic Trigger: Final Secret of the Illuminati. “I had already incorporated into Illuminatus a variation on the Lovecraft mythos” … which he states means a Cthulhu Cult -like group helping alien entities.

1976: Jeffrey P. Miller, in a scourging review of a new Arkham Press anthology, reviewed in Science Fiction Review for May 1976. “No Arkham anthology would be complete without a few stories in August Derleth’s Cthulhu Mythos (in which the good gods and the bad gods play macrocosmic cowboys and indians, as opposed to the Lovecraft Mythos, seldom used these days, in which mankind stands alone against unknown and extra—moral forces)”.

That’s as far back as the online archives can take me, though the Masterplots annuals for 1969 and 1971 do each appear to have a bare noting of items as belonging to “Lovecraft’s mythos”. Presumably this was on their plot summaries for Derleth-approved work which had recently appeared.

Can anyone find more substantial pre-1976 uses? Uses that are not just late Derleth in letters or newsletters, trying to lay a cloaking glamour over his own ‘collaborations’?