What is M's real name in James Bond?

The title "M" is believed to have been derived by creator Ian Fleming from the first real-life head of His Majesty's Secret Service, Mansfield Smith-Cumming, who used his initial "C" to indicate when he had seen a paper and so became referred to as "C", a practice that carried on with his successors. Other influences on the character include Admiral John Godfrey, Fleming's superior in British Naval Intelligence during World War II, and "R," the secret service employer of W. Somerset Maugham's Ashenden. The "M" may be an abbreviation for Minister, referring to his title as head of MI6. In Fleming's novel The Man with the Golden Gun M's true identity is revealed as Rear Admiral Sir Miles Messervy; this may be where the M comes from, but does not explain the films because there has been more than one M. In the 2006 film version of Casino Royale, it is suggested the letter may likewise refer to the actual name of the later, female M.  more