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
Throughout the programme's long history, there have been revelations about the Doctor that have raised additional questions. In "The Brain of Morbius" (1976), it was hinted that the First Doctor might not have been the first incarnation (although the other faces depicted might have been incarnations of the Time Lord Morbius). In subsequent stories the First Doctor was depicted as the earliest incarnation of the Doctor. In "Mawdryn Undead" (1983), the Fifth Doctor explicitly confirmed that he was then currently in his fifth incarnation. Later that same year, during 1983's 20th Anniversary special "The Five Doctors", the First Doctor enquires as to the Fifth Doctor's regeneration; when the Fifth Doctor confirms "Fourth", the First Doctor excitedly replies "Goodness me. So there are five of me now." In 2010, the Eleventh Doctor similarly calls himself "the Eleventh" in "The Lodger". In the 2013 episode "The Time of the Doctor," the Eleventh Doctor clarified he was the product of the twelfth regeneration, due to a previous incarnation which he chose not to count and one other aborted regeneration. The name Eleventh is still used for this incarnation; the same episode depicts the prophesied "Fall of the Eleventh" which had been trailed throughout the series.