Most of Grant Allen's fiction is now forgotten and nearly all of it is out of print. His detective stories, however, many of which first appeared in the Strand Magazine, have earned critical praise, and volumes of his detective fiction are now sought by book collectors. Allen's chief contribution to the genre, An African Millionaire: Episodes in the Life of the Illustrious Colonel Clay (1897), was listed by Ellery Queen as one of the "cornerstones" of detective fiction and cited by Hugh Greene as "one of the most amusing collections of crime stories ever written." Besides creating the first great rogue of mystery fiction--the illustrious Colonel Clay--Allen produced two lively series of stories featuring female amateur sleuths, collected in Miss Cayley's Adventures (1899) and Hilda Wade: A Woman with Tenacity of Purpose (1900), as well as two novels in which detectives play parts, The Scallywag (1893) and A Splendid Sin (1896), and several other novels and stories that may be linked, albeit loosely at times, to the mystery genre.
