James Moriarty

James Moriarty was the arch-enemy of Sherlock Holmes.

History
In order to investigate Baron Maupertuis, Moriarty used the alias O'Connor and donned a ginger wig as part of his disguise. He also wrote a paper on the mathematics of folding higher dimensions. (PROSE: All-Consuming Fire) Moriarty died in 1893. (PROSE: The Found World)

Contradicting other accounts, Moriarty also seemed to exist in the Land of Fiction, suggesting he was a fictional character. (COMIC: Character Assassin)

once claimed that the Seventh Doctor flattered himself by thinking of himself as being the Moriarty to the Master's Holmes when he actually provided merely "adequate opposition worthy of very little attention". (AUDIO: The Two Masters)

The Eleventh Doctor, while dressed like Sherlock Holmes, once compared the Great Intelligence to Moriarty, calling it "the clever one". (TV: The Snowmen)

Behind the scenes

 * Moriarty has been played by Paul Freeman in the film Without a Clue, Philip Locke on stage and Ronald Pickup in a radio play.
 * Doctor Who producer Barry Letts and script editor Terrance Dicks confirmed that the Master was devised as "the Moriarty" to the Doctor's "Sherlock Holmes". (DOC: Life on Earth)