Two people I have not mentioned so far, but who played key roles in the development of the BBC's new Sci-Fi series are David Whitaker and Mervyn Pinfield.
The latter was Associate Producer on early Doctor Who, and would later direct part of The Sensorites, the whole of The Space Museum, and the first two episodes of Planet of Giants.
His area of expertise was in the technical side of things - such as the development of the famous title sequence. Cast whom he directed recall how his passion for the camera work and other technical requirements made him somewhat distant from the actors and story telling. He is supposed to have invented an early form of teleprompter / autocue, which he called a Piniprompter.
David Whitaker was very much a writer and a stories man. He was Doctor Who's first Story Editor. He would go on to write many highly regarded stories himself, including both Troughton Dalek tales. His other Dalek related work included the Century 21 comic strips and the first Doctor Who stage play - The Curse of the Daleks.
Whitaker worked closely with Verity Lambert in putting together the story ideas for the new series. As previously mentioned, one story which may have opened the series was "The Miniscules" or "The Giants" wherein the Doctor, Susan and their new companions would be miniaturised in Ian's school science lab. Whitaker approached other writers such as Anthony Coburn, Terry Nation, Malcolm Hulke, and Moris Fahri.
Stories were developed, dropped and moved around.
Stories which were lost included Fahri's "The Fragile Yellow Arc of Fragrance" (don't ask...) and "Farewell Great Macedon" (about Alexander the Great). Anthony Coburn had a story about a planet of robots - "The Masters of Luxor". Hulke's first contributed idea to the programme was called "The Hidden Planet" and would feature another Earth on the other side of the Sun, identical to ours except everything would be backwards or opposite. (This concept would eventually be seen as a Gerry Anderson movie). A Terry Nation story which never made it was "The Red Fort" - a historical set during the British Raj. It was actually the success of the Daleks which put an end to it.
The story eventually decided upon to open the series (somewhat reluctantly) was one written by Australian writer Anthony Coburn, and its first episode was called An Unearthly Child. Its production is a story in itself, as we will see when we look at what has come to be known as "The Pilot"...