Walter Peter Swanwick (29 September 1922 – 14 November 1968) was a British actor best remembered as the "Supervisor" (sometimes called the Controller) in the 1967 TV series, The Prisoner. Swanwick's film career began with bit parts in films such as The African Queen (1951), and he became a recognisable face on British TV during the mid-1960s when he featured in a number of series, including The Avengers and Danger Man, where he first worked with Patrick McGoohan, who later co-created and starred in The Prisoner. Swanwick had major health problems in the 1960s that resulted in his undergoing multiple operations and leaving him with a short time to live. Swanwick played the non-singing part of Herr Zeller in the original London stage production of The Sound of Music. (Via Wikipedia)