Following the success of the 'Thunderbirds', 'Joe 90' and other series, Gerry Anderson produced 'The Secret Service' in 1969, the last to use his trademark supermarionation process. The series also made unprecedented use of live action footage, which was blended in with close-ups of the supermarionated puppets. Anderson has often been quoted as calling 'The Secret Service' his favourite puppet program. Only one series, which ran for 13 episodes, was made.
The series followed the adventures of Father Stanley Unwin, a priest who moonlights as a secret agent for an organisation called 'B.I.S.H.O.P.' (British Intelligence Service Headquarters, Operation Priest). In a somewhat unusual occurrence, for an animation series, the voice and (when required) physical actions of 'Father Stanley Unwin' were actually performed by an actor named 'Stanley Unwin', a popular British comedian of the time, who was best known for speaking in a form of gibberish he called "Unwinese", a gimmick which was utilised in the series to allow the fictional Unwin to confuse his enemies through coded messages.