Major The Hon. John Wickham Gascoyne Beresford Steed usually known as John Steed, is a fictional character and the central protagonist on the 1960s British spy series The Avengers and its 1970s sequel The New Avengers, played by Patrick Macnee in both; by Donald Monat in the South-African radio series adaptation of The Avengers; by Ralph Fiennes in the 1998 film of the same name and by Julian Wadham in various audio adventures from Big Finish Productions.
Steed is a secret agent working for an unnamed branch of British intelligence. He was teamed with a variety of partners, including Dr. David Keel (1961), Dr. Martin King (1962), Venus Smith (1962–1963), Cathy Gale (1962–1964), Emma Peel (1965–1968), Tara King (1968–1969), Lady Diana Forbes-Blakeney (1969), Purdey, and Mike Gambit (both 1976–1977).
Source : Wikipedia