Fu Manchu, also known as The Doctor and the Devil Doctor, was a warlord and the leader of the Chinese organized crime. There was little information about his background, except he was rumoured to have grown up during the Opium Wars in China and as a result abhorred the British with a vengeance. In 1898, The Doctor moved his operations to Limehouse where he became a personal and professional rival of James Moriarty. The Doctor led his forces in stealing Selwyn Cavor's Cavorite to fuel his own airship to wage a gang war against Moriarty. However, Moriarty manipulated the League into retrieving the Cavorite and powering his own airship to bombard Limehouse. The Doctor engaged Moriarty in an aerial battle and survived the confrontation after the League defeated Moriarty.
In 1948, Limehouse was purged by the INGSOC Party, forcing The Doctor to relocate to New York City. He is also a relative of Doctor Sax and was once falsely believed to be an ancestor of Dr. No.
The Doctor is based on Fu Manchu, a character created by Sax Rohmer that first appeared in The Insidious Dr Fu Manchu (1913). In the comics he is never referred to by name as the character is not in the public domain in the United Kingdom.
The Doctor's Limehouse base in a tunnel underneath the Thames is from Rohmer's 1934 novel The Trail of Fu Manchu.