10 things you didn't know about Sherlock Holmes

5: The absent arch-villain

Sherlock's supposed arch-nemesis Professor Moriarty only appeared in two of the original stories.

It's a common misconception that the devious Moriarty was a recurring villain in Conan Doyle's tales – a sort of Joker or Lex Luthor figure. The first time he appeared in a Sherlock adventure he was killed by Holmes at the end, and only turned up once again in a prequel tale. His inflated reputation stems not from his actual reported misdeeds, but from Holmes's high opinion of him as a criminal genius.

6: A case of love?

Sherlock Holmes, like Doctor Who, was generally immune to the sexual charms of women. Yet there was one lady he was rather wild about.

She was Irene Adler, a beautiful opera singer whom Holmes was once hired to investigate. She actually got the better of the great detective and managed to elude him, which could account for Holmes's strong feelings for her. According to Watson, "in his eyes she eclipses and predominates the whole of her sex", but the doctor also maintained that Holmes did not love her. Holmes fans have never quite believed this, however, and there have been many post-Conan Doyle tales written about the romantic attachment between the detective and the singer.