Rex Tucker Rex Tucker directed the " Doctor Who " story " The Gunfighters " and contributed to the lyrics of " The Ballad of the Last Chance Saloon " . However , he did request that his director ' s credit be removed from the closing captions of " The O . K . Corral " following a disagreement with Innes Lloyd over its editing . He was credited for all the others . Tucker also had a significant impact upon the very origins of " Doctor Who " . Despite a lack of screen credit , he was the programme ' s first producer . Appointed in May 1963 as an " interim " or " caretaker " producer until Sydney Newman could find a permanent replacement , Tucker was also , for many months , the director of " An Unearthly Child " . Had the show been filmed for its original 24 August 1963 launch date , he would have been " Doctor Who " s first director . On 28 May 1963 , he became the first in a very long line of people to send a memo to his superiors about the unsuitability of Lime Grove Studio D for " Doctor Who " . His memo to Donald Wilson worked , inasmuch as it got Wilson , Ayton Whitaker and Ian Atkins to accept the word of an experienced director that Lime Grove simply didn ' t meet the technical requirements of a programme like " Doctor Who " . It also resulted in Wilson supporting the notion of Riverside Studios as an acceptable substitute , should studios at Television Centre prove unavailable . In the end , of course , Lime Grove " would " be used , but Tucker ' s initial memo had the effect of getting important players mobilised in the fight for facilities . It also resulted in what would become the basic facilities priority of the 1960s : TC first , then Riverside , then — as the very last resort — Lime Grove . He also began the process of staffing for the show . He was the original point of contact between " Doctor Who " and Tristram Cary . Though Cary would ultimately not provide the theme and incidental music for the first serial , he would be in place to score " The Daleks " and " The Dalek Invasion of Earth " , cementing some musical punctuation into the fabric of " Doctor Who " . Tucker would also bring back Cary for " The Gunfighters " . Tucker was also involved in initial casting . He was the first person to offer the role of the Doctor to an actor . Had Hugh David accepted , Verity Lambert would have been saddled with a star she had not chosen . He also held casting sessions for the part of Susan and Miss McGovern , a character who would become Barbara Wright . As with the Doctor , he was not able to select an actor for either of these parts . He was also responsible for reducing C . E . Webber ' s contributions to early " Doctor Who " . He rejected Webber ' s " The Giants " , the first of three attempts to write a story about a miniaturised TARDIS crew . This story would have been the programme ' s first serial , the one Tucker was slated to direct . Instead , Donald Wilson and he tapped Anthony Coburn to bring his story , then called " The Tribe of Gum " , to the first position , but to rewrite it so that it incorporated some elements of Webber ' s first episode . He was known to have worked out a production schedule for the first serial that would have allowed recording to begin about 19 July 1963 . On 1 July , however , Donald Baverstock ' s office informed the " Doctor Who " office that the series would not begin transmission until 9 November . This meant that the recording of " The Tribe of Gum " , as it was still known , would largely happen whilst Tucker was on his scheduled vacation . For a brief time , he was assigned to the second story and then bumped to the fourth story , which was , at the time , the Terry Nation script ; he might have become the director who introduced the Dalek s . It is unclear , however , what preparatory work , if any , he did for that serial . By the time he left for holiday on 30 August he had begged off " Doctor Who " and been re - assigned to " Madame Bovary " , a serial on which he would again be joined by Tristram Cary . ( REF : " The First Doctor Handbook " )