A footnote at the end of An Inhabitant of Carcosa states, "Such are the facts imparted to the medium Bayrolles by the spirit Hoseib Alar Robardin." As Hoseib Alar Robardin is the narrator (the titular inhabitant), he is a native of Carcosa and lived at some point in the ancient past. His name sounds vaguely Arabic, but is not.
The spirit's middle name is also commonly the name of a city in the Carcosa Mythos. The name H.A. Robardin is given as the proprietor of The Yellow Sign Hotel in The Rest Of Your Life.
See also Hoseib Alar and Doctor H.A. Robardin.