Camelot refers to a kingdom, which in most realities is or was once under the rule of King Arthur. Commonalities between the realities seem to be the existence of knights held to a code of chivalry, overt existence of magic, and court intrigue.
In An Incubus in King Arthur's Court, Dhiar found himself summoned back to Camelot by Morgaine, a sorceress. He had been there before and was known to Morgaine, and although he knew of her son Mordred, clearly the two had not met. He also interacted with a knight of Arthur's Round Table, Galahad.
Dhiar has, in the past, fought on the side of good against a common foe with his friend Hawkye L. Narasumas.