Read "Dominion" at The Eldritch Dark:
This poem from Clark Ashton Smith (CAS) originally appeared in the June 1935 issue of Weird Tales magazine, which apparently also featured a story (by Dorothy Quick) called "The Horror in the Studio". The mind boggles...
The subject of "Dominion" would appear to be Demeter, one of the twelve Olympians of Greek myth. Demeter is traditionally thought of as a goddess of agriculture and the earth, but in a further tradition she was also said to have power over the underworld, and was linked to an ancient cult of the dead. This stanza particularly would seem to confirm those associations:
Yea, still thy whisper moves, and magically stirs
To life the shapeless dust in shattered sepulchers;
And in dark bread and wine thou art the untold leaven.
I have no further evidence that Demeter is the subject of this poem (beyond my own interpretation), but the title "Dominion" certainly reinforces the idea of this being an ode to a deity.