There was an “Armitage Handout on Lovecraftian Arthuriana” at the scholarly symposium at NecronomiCon 2017. Basically, a preliminary but useful list of King Arthur work which elides in some way with Lovecraft.

This has now been revised and updated as “Mergers of the Matter of Britain and Lovecraft’s Cthulhuan Mythos: A Preliminary Bibliography (Revised)” (May 2019), which is online and public.

Picture: Merlin, by a young Howard Pyle.