The Avengers is a British espionage television programme, created in 1961, that ran for 161 episodes until 1969. It initially focused on David Keel (Ian Hendry), aided by John Steed (Patrick Macnee). Hendry left after the first series; Steed then became the main character, partnered with a succession of assistants. His most famous assistants were intelligent, stylish and assertive women: Cathy Gale (Honor Blackman), Emma Peel (Diana Rigg), and Tara King (Linda Thorson). The series ran from 1961 until 1969, screening as one-hour episodes for its entire run. The pilot episode, "Hot Snow", aired on 7 January 1961. The final episode, "Bizarre", aired on 21 April 1969 in the United States, and on 21 May 1969 in the United Kingdom.