Arthurian vs Lovecraftian Themes

Like many avid readers I have my favorite concepts and themes, but since I was 14 there were two theme sets that really had an odd appeal to me. Those two would be the Arthurian cycle of stories and the works of HP Lovecraft. I believe it came from an odd weekend, where in one rainy Saturday, I read through Rosemary Sutcliff’s Sword at Sunset while the movie “Excalibur” played in the background. Later that afternoon would be the first time I read At the Mountains of Madness, by Lovecraft. In my mind those stories rolled around and seem to echo off of each other. 
In all their variety there could not be two story cycles that are radically different but still fanciful. From the most historical rooted Arthurian tale to the most fantastic themed medieval romance, there is always an underpinning of the otherworldly to Arthurian tales. Also included though is always a bit of hope and a bittersweet tone of the frailty of human aspirations and lives. In many ways it is very human story.
The cosmic horror or eldritch horror story is a very different beast all together, when it comes to fiction. All of the ‘Cthulu Mythos’ stories by Lovecraft and other writers are also otherwordly, yet the very alien tones and sense of surreality makes it very different than Arthurian stories. Both are dealing with otherwordly or surreal elements, but one is very human and the other is very ‘unhuman’.