“The Red-Headed League” was the second Sherlock Holmes story to appear in The Strand Magazine, preceded only by “A Scandal in Bohemia.” It was published in August 1891 and set the previous year, a fact that is established by the date of The Morning Chronicle that Jabez Wilson brings to show Holmes: 27 April 1890. There is, in fact, a slight and unexplained discrepancy in the dates, given that the notice announcing the dissolution of the Red-Headed League two months later is dated 9 October 1890, not, as one would expect, in late June. However, the year is not in question, and this appears to be nothing more than an oversight.

Although Sherlock Holmes had already appeared in two novels, A Study in Scarlet and The Sign of Four, there are clear signs in “The Red-Headed League” that the great detective is still in the process of being introduced to a new readership in the Strand Magazine. In the process of this introduction, his character is still developing and changing, as is his relationship with Watson. Watson does not live with Holmes in this story and is not on such easy terms with him as he is in the later narratives. In the first paragraph, he apologizes for his intrusion and is about to leave when he sees that Holmes is with a client. Watson also gives the reader a great deal of information about Holmes, his habits and tastes, and even his physical appearance, which is too familiar to require description in the later stories (Holmes is, after all, one of the few characters in English fiction who can be identified instantly from a silhouette).

Watson mentions that Holmes is thin, and has a “hawk-like nose.” He has the habit of putting his finger-tips together “when in judicial moods.” He smokes a black clay pipe and refers to a particularly intriguing conundrum as “a three-pipe problem.” He loves music, which he plays, composes, and listens to with rapt attention; he prefers the work of German composers to that of the Italians and the French. Most significantly, Watson refers to the curious duality in Holmes’s personality. When he is listening to violin music at a concert, he appears to be a languid, poetic dreamer, but as soon as he is engaged in an absorbing case, he is as keen and tenacious as a bloodhound.

The idea that Holmes is a sensitive aesthete, a lover of music and literature, is introduced in “The Red-Headed League.” The previous story in the Strand Magazine, “A Scandal in Bohemia,” shows Holmes in an uncharacteristic role, failing in his task and being outwitted by his adversary. However, even in this story, Watson portrays him as a cold and logical calculating-machine, his admiration for Irene Adler based entirely on his respect for her intellect. In the first paragraph, he observes:

Grit in a sensitive instrument, or a crack in one of his own high-power lenses, would not be more disturbing than a strong emotion in a nature such as his.

In A Study in Scarlet, the first Holmes novel, published in 1887, Watson goes even further. Upon finding out that Holmes knows nothing of Thomas Carlyle and is even ignorant of the fact that the earth orbits the sun, he compiles the following list:

Sherlock Holmes—his limits. 
1. Knowledge of Literature.—Nil.
2. Philosophy.—Nil.
3. Astronomy.—Nil.
4. Politics.—Feeble.
5. Botany.—Variable. Well up in belladonna, opium, and poisons generally. Knows nothing of practical gardening.
6. Geology.—Practical, but limited. Tells at a glance different soils from each other. After walks has shown me splashes upon his trousers, and told me by their colour and consistence in what part of London he had received them.
7. Chemistry.—Profound.
8. Anatomy.—Accurate, but unsystematic.
9. Sensational Literature.—Immense. He appears to know every detail of every horror perpetrated in the century.
10. Plays the violin well.
11. Is an expert singlestick player, boxer, and swordsman.
12. Has a good practical knowledge of British law.

The tenth item on this list is the only one that hints at any aesthetic sensibility, and Watson describes Holmes merely as a competent technical performer on the violin, rather than as a lover of music. The point he makes, and continually emphasizes, in A Study in Scarlet, is that Holmes has no use for any knowledge unless it is useful to him in his profession. He is a detective and nothing but a detective. In “The Red-Headed League,” however, Holmes is characterized quite differently. His use of Latin may be dismissed as the result of a Victorian classical education, but at the end of the story, he quotes in French from a letter written by Gustave Flaubert to George Sand, a feat hardly consistent with the complete ignorance of literature Watson describes in the earlier work.

Conan Doyle was not part of the Aesthetic Movement that flourished in France and England at the time when he began to write the Sherlock Holmes stories, but he was aware of the work of its members and perhaps more influenced by them than is generally admitted. He first met Oscar Wilde in 1889, two years before “The Red-Headed League” appeared, and the name of William Morris, another doyenne of nineteenth-century aestheticism, actually appears in the text, as an alias used by Duncan Ross (who shares a surname with Wilde’s lover, Robert Ross). Whether or not he is intended to be read as a Wildean aesthete, the Sherlock Holmes who quotes Flaubert and listens with languid rapture to violin music is a very different character from the icily logical calculating machine who first appeared four years earlier in A Study in Scarlet.