AP Films or APF, later becoming Century 21 Productions, was a British independent film production company of the 1950s until the early 1970s. The company became internationally known for its imaginative children's action-adventure marionette television series – most significantly Thunderbirds – produced for British ITV network companies Associated-Rediffusion, Granada, ABC and ATV. At its height, the company employed more than 200 staff. Origins Established in 1956 by editor-director Gerry Anderson and cinematographer Arthur Provis, following the liquidation of their employer Polytechnic Films, AP Films was set up. They took with them producer Reg Hill, cinematographer John Read and secretary, then known as Sylvia Thamm. Thamm would later become Anderson's second wife. The company was created with the intention of it becoming a conventional film production house. With no commissions and funds running low, APF were approached with an offer of collaboration with children's author Roberta Leigh and her colleague Suzanne Warner to produce the puppet TV series The Adventures of Twizzle for Associated-Rediffusion. With some reluctance, the company took on the commission and the programme was such a success that it immediately led to a further collaboration with Leigh for the first series of Torchy the Battery Boy. In 1959, Provis left the company amicably following disagreements with Anderson over future strategy. APF then went on to make its first wholly independent production of Four Feather Falls, a puppet Western created by Barry Gray who was better known for his musical contributions to the company's productions, for Granada Television. In 1960, APF made a live-action thriller feature film, Crossroads to Crime, for Anglo-Amalgamated, and a series of TV advertisements for a London travel company. Success Returning to filming with puppets, but with a change in direction and the adoption of a technique by which mouth movements were synchronised with recorded dialogue in a process that Anderson dubbed "Supermarionation", the company then filmed its best-known productions – a succession of futuristic science-fiction action-adventure series, all made for ATV. Supercar was made between 1960 and 1961, Fireball XL5 in 1962, Stingray in 1964 – the first British children's TV series to be filmed exclusively in colour – and Thunderbirds between 1964 and 1966. Following the completion of Fireball XL5, ATV owner Lew Grade had purchased the company, becoming managing director, with the Andersons, Hill and Read remaining as directors. Productions The following were made under the AP Films name. The Adventures of