#OTD in 1923.
Dorothy L. Sayers' fictional English detective and bibliophile, Lord Peter Wimsey, makes his first appearance in the novel Whose Body?, published by Boni & Liveright in the United States. The first U.K. edition follows in October from T. Fisher Unwin.
Whose Body? at Project Gutenberg:
https://gutenberg.org/ebooks/58820