Edmond Hamilton created the “Hugh Davidson” pseudonym for “Vampire Village” (Weird Tales, November 1932). I’m not sure why since he has no other story under his own name in the issue, the usual reason Pulp writers used nom de plums. Another common reason is they don’t want their name associated with a “shocking” element that might sully their name. “Vampire Village” doesn’t have any such element. (Did Ed consider writing pure horror a way to sully his name in the Science Fiction market? I doubt it, since he was one of the stars of a horror magazine.)
Perhaps Ed was worried his name was appearing too often in Weird Tales? Maybe he wanted to cultivate a second name to increase sales potential? One for his horror tales, though he had written horror under his own name. Or since he was using a psychic investigator, Dr. John Dale, he didn’t want any negative comparisons over Seabury Quinn’s Jules de Grandin such as his friend E. Hoffman Price had got with Peter D’Artois?
An unrelated tale, “Snake-Man” appeared with the Davidson label in Weird Tales, January 1933. Not a vampire or Dale story, it is horror rather than Science Fiction. The Hugh Davidson pseudonym was attached only to horror tales. They all seemed to be receiving Jayem Wilcox illustration as well.
Whatever the reason when he wrote the short novel “The Vampire Master” (Weird Tales, October 1933-January 1934) he may have chosen to use Hugh Davidson again because readers associated the name with “Vampire Village”. When Hamilton wrote of Dr. John Dale a second time in “The House of the Evil Eye” (Weird Tales, June 1936) it only made sense to use the pseudonym again.
The secret of the pseudonym wasn’t kept for long as Charles H. Bert outed him in July 1936 with “…I like Hugh Davidson’s House of the Evil Eye very much, although I know that Davidson is the nom de plum of Edmond Hamilton. You see, the style of writing betrays him…” Hamilton never used the pseudonym in Weird Tales again after this.
Hamilton did revive it in 1951 when he had two comic stories in Mystery in Space #2 (June-July 1951) and again in Strange Adventures #13 (October 1951). This time it was because Ed had two stories in the same issue. Would anyone even remember Hamilton had been Davidson in 1932?
New Mutants #3 (September 2009) features a villain named Hugh Davidson. I wonder if this is coincidence or was Zeb Wells a fan of DC Comics or the Pulps? Davidson is one of a number of personalities that the villain Legion possesses. I strongly suspect the name is coincidental.