What is the first name of Sherlock Holmes' arch enemy, Professor Moriarty?

Professor James Moriarty is a fictional character in some of the Sherlock Holmes stories written by Sir Arthur Conan Doyle. Moriarty is a machiavellian criminal mastermind whom Holmes describes as the "Napoleon of crime". Doyle lifted the phrase from a Scotland Yard inspector who was referring to Adam Worth, a real-life criminal mastermind and one of the individuals upon whom the character of Moriarty was based.

The character was introduced primarily as a narrative device to enable Doyle to kill Sherlock Holmes, and only featured in two of the Sherlock Holmes stories. However, in adaptations, he has often been given a greater prominence and treated as Sherlock Holmes' archenemy.