The Doctor (Doctor Who)
The Doctor is the title character in the long-running BBC science fiction television programme "Doctor Who". Since the show's inception in 1963, the character has been portrayed by thirteen lead actors. In the programme, "the Doctor" is the alias assumed by a centuries-old alien—a Time Lord from the planet Gallifrey—who travels through space and time in the TARDIS, frequently with companions. The transition to each succeeding actor is explained within the show's narrative through the plot device of "regeneration", a biological function of the Time Lord race that allows a change of cellular structure and appearance with recovery following a potentially fatal injury.
Doctor Who (season 7)
The seventh season of British science fiction television series "Doctor Who" began on 3 January 1970 with Jon Pertwee's first story "Spearhead from Space" and ended with "Inferno".Jon Pertwee makes his first appearance as the Third Doctor replacing Patrick Troughton in the role. Caroline John makes her first appearance as companion and assistant Liz Shaw in "Spearhead from Space" and last in "Inferno".Nicholas Courtney returns as Brigadier Lethbridge-Stewart and he would continue to make regular appearances in "Doctor Who" until season 12.