10 Behind The Scenes Secrets From Doctor Who: An Unearthly Child
6. William Russell Was A 'Physically Perfect, Strong And Courageous Man'
The general shape of the original TARDIS team was more or less unchanged through the writing process. C.E. Webber wrote Bridget/Biddy as the teenaged girl who would be traveling with the Doctor. Her teachers would be Miss Lola MacGovern and Cliff.
Cliff was the heroic male figure of the piece, very different from the image that was sought for The Doctor. In the early drafts, he was quite a violent man. Some of these character traits remain in the other episodes of the first serial, while in An Unearthly Child he is slightly more reasoned than anything else.
William Russell had previously starred as Sir Lancelot in the ITV series that ran from 1956. In being cast as the first male companion to the Doctor, Russell played Ian Chesterton, who was a retooling of 'Cliff'.
Ian Chesterton, in An Unearthly Child, is a science teacher, while Barbara Wright is a history teacher. These character descriptions were meant as a clue as to how the show was to proceed, dealing with the mix of both science and history in each serial.