Doctor Who – The Ultimate Adventure Doctor Who – The Ultimate Adventure Doctor Who – The Ultimate Adventure was a 1989 stage play written by Terrance Dicks, based on the long-running British science fiction television series "Doctor Who". The play was staged at twenty theatres around Britain, commencing 23 March 1989. It initially starred Jon Pertwee (who had played the Third Doctor in the series) as the Doctor. On 29 April Pertwee was ill, so understudy David Banks, who portrayed the Cyber Leader in the series from "Earthshock" onwards, played the Doctor for the matinee and evening performances. Pertwee continued in the role until 3 June
The Doctor (Doctor Who) "definite sense of Englishness". When Hartnell left the programme after three years due to ill health, the role was handed over to character actor Patrick Troughton. , official television productions have depicted thirteen distinct incarnations of the Doctor. The longest-lasting on-screen incarnation is the Fourth Doctor, played by Tom Baker for seven years. Within the narrative, these changes were explained as regeneration, a biological process which heals a Time Lord when their incarnation is about to die. Consequently, the Time Lord is given a wholly new body. In "The Deadly Assassin", the concept of a regeneration limit is introduced, giving