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
The companion figure – generally a human – has been a constant feature in "Doctor Who" since the programme's inception in 1963. One of the roles of the companion is to be a reminder for the Doctor's "moral duty". The Doctor's first companions seen on screen were his granddaughter Susan Foreman (Carole Ann Ford) and her teachers Barbara Wright (Jacqueline Hill) and Ian Chesterton (William Russell). These characters were intended to act as audience surrogates, through which the audience would discover information about the Doctor who was to act as a mysterious father figure. The only story from the original series in which the Doctor travels alone is "The Deadly Assassin" (1976). Notable companions from the earlier series included Romana (Mary Tamm and Lalla Ward), a Time Lady; Sarah Jane Smith (Elisabeth Sladen); and Jo Grant (Katy Manning). Dramatically, these characters provide a figure with whom the audience can identify, and serve to further the story by requesting exposition from the Doctor and manufacturing peril for the Doctor to resolve. The Doctor regularly gains new companions and loses old ones; sometimes they return home or find new causes — or loves — on worlds they have visited. Some have died during the course of the series. Companions are usually human, or humanoid aliens.