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 millennia-old humanoid alien, a Time Lord 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 fatal injury. A number of other actors have played the character in stage and audio plays, as well as in various film and television productions. The Doctor has been well received by the public, with an enduring popularity leading The Daily Telegraph to dub the character "Britain's favourite alien", while abroad the character has come to be seen as a British cultural icon. The Doctor has also been featured in films and a vast range of spin-off novels, audio dramas and comic strips. Currently, David Tennant portrays the Fourteenth Doctor, succeeding Jodie Whittaker at the end of "The Power of the Doctor" (2022). Tennant previously played the Tenth Doctor between 2005 and 2010, with his current tenure marking the first time an actor has returned to the role as a new incarnation. He will feature in three specials celebrating Doctor Who's 60th anniversary in 2023 before Ncuti Gatwa takes over as the Fifteenth Doctor in 2024. From Wikipedia