M (James Bond)M - the code letter for James Bond's boss and fictional head of the British Secret Intelligence Service MI6.
In the Bond books M is named as Admiral Sir Miles Messervy (the name, hinted at throughout the series, was finally revealed in The Man with the Golden Gun, Ian Fleming's final Bond novel). In the movies he is not named, but various hints indicate that he is intended to be the same person.
In the books M clearly has a liking for Bond, and they have obviously had a long professional relationship. M bends the rules for Bond on several occasions. At one point Bond attempts to assassinate M, as a result of extreme Soviet brainwashing, but M insists that Bond is rehabilitated rather than punished. In Colonel Sun M is kidnapped, and Bond goes to great lengths to rescue him. In the post-Fleming books M protects Bond even more from the new, less agressive, climate in the Secret Service, saying that 'sometime this country will need a blunt instrument'. In the movies the relationship is similar, although Judi Dench's M is initially distrustful of Bond.
In the movies the part of M was played by Bernard Lee from the first movie, Dr. No, until Moonraker (1979). The character did not appear in For Your Eyes Only (1981), and was subsequently played by Robert Brown and then Judi Dench. Robert Brown's character is intended to be the same person played by Bernard Lee. Judi Dench clearly plays a new person appointed to the position of M, possibly Barbara Mawdsley, who is named as a female M in the later Bond books.
The M in the Bond books is believed to have been a composite character based on Rear-Admiral John Godfrey (Ian Fleming's former boss in the Department of Naval Intelligence), Maxwell Knight, former head of counter-subversion in MI5 and Maurice Buckmaster, head of the F Section of the SOE.