History TheNthDoctor / DoctorWho

** Regenerated in "[[Recap/DoctorWho2022CENThePowerOfTheDoctor The Power of the Doctor]]" after the Master aims a destructive blast from the Qurunx at her, although she holds it off long enough to have a final moment with and see off Yaz.

** The first Doctor to be played by the same actor as another incarnation, with the Thirteen Doctor having mysteriously regenerated into this familiar form at the end of "The Power of the Doctor". Tennant will star in three specials in November 2023 to commemorate the show’s 60th anniversary, before regenerating into the Fifteenth Doctor.

* The 1976 Fourth Doctor serial "[[Recap/DoctorWhoS13E5TheBrainOfMorbius The Brain of Morbius]]" suggested that the Doctor had at least eight different incarnations before the First Doctor. This was largely ignored by the fandom, who accepted the twelve-regeneration limit and the First Doctor as the original incarnation of the Doctor, and later retconned into them being previous incarnations of Morbius, but "The Timeless Children" forced the episode back into public consciousness by [[spoiler:confirming that they are the unseen incarnations of the Timeless Child, who eventually becomes the Doctor.]] The faces representing these incarnations are actually mugshots of various men on the story's production team[[note]]from top-left of [[https://static.wikia.nocookie.net/tardis/images/b/b9/Morbius_Doctors_bigger.JPG this image]]: Christopher Barry, Robert Banks Stewart, Christopher Baker, Creator/PhilipHinchcliffe, Douglas Camfield, Graeme Harper, Martin Jurgens, and George Gallaccio[[/note]], and they technically never portrayed the Doctor in any media, but producer Creator/PhilipHinchcliffe fully intended to make the "Morbius Doctors" canon.

* Creator/DavidBradley (portrayed William Hartnell and Hartnell in-character as the First Doctor) in the 2013 docudrama ''Film/AnAdventureInSpaceAndTime''. He reprised the role within the show's canon for the 2017 Christmas Special, [[Recap/DoctorWho2017CSTwiceUponATime "Twice Upon a Time"]] (as Hurndall had also died), and has subsequently voiced the First Doctor in Big Finish audios.

* [[Recap/DoctorWhoS38E5FugitiveOfTheJudoon "Fugitive of the Judoon"]] introduces Creator/JoMartin as an incarnation of the Doctor whose position in the timeline is unknown, as neither she nor Thirteen remember ever being each other. As Doctor Moon was only confirmed to be the Doctor by WordOfGod, this also makes Martin's incarnation the first nonwhite one to be confirmed on-screen. [[spoiler:After the events of "The Timeless Children", she's likely a past incarnation who worked for [[NoSuchAgency the Division]].]]

* Not only is changing race possible, so is changing gender. Though first seen in a parody special, the Doctor later mentions a friend named the Corsair in [[Recap/DoctorWhoS32E4TheDoctorsWife "The Doctor's Wife"]], who had the same tattoo in all his — or her — regenerations. This was further confirmed as canonical when Missy appeared as the first female incarnation of the Master.

* One recurring Big Finish character is a Time Lord criminal who has all of their previous incarnations still active in their mind, and is identified by the number of incarnations currently present (i.e. the One, the Two, the Three, and so on). Four of their incarnations have appeared in person: the Eight (Tim [=McMullan=]), the Nine (John Heffernan), the Eleven (Mark Bonnar), and the Twelve (Julia [=McKenzie=]).
* Original to Big Finish, Cardinal Ollistra (Jacqueline Pearce) features in stories set during the Time War. ''The Side of the Angels'' introduced her predecessor (Carolyn Pickles), who had regenerated before the war. Pearce passed away in 2018, but the Carolyn Pickles incarnation was eventually reintroduced to the Time War beginning in 2022, the explanation being that this past Ollistra was recreated from the Matrix supercomputer (essentially the sum of all Time Lord memory) to work in Gallifrey's War Room whilst the current Ollistra led operations off-world.

* The three incarnations of Franchise/IrisWildthyme who appear in the Eighth Doctor Adventures were physically based on Beryl Reid, Shirley Bassey, and the young Jane Fonda. When she subsequently appeared in Big Finish, she was voiced by Katy Manning.

** The first Doctor to be played by the same actor as another incarnation, with the Thirteen Doctor having mysteriously regenerated into this familiar form at the end of [[Recap/DoctorWho2022CENThePowerOfTheDoctor "The Power of the Doctor"]]. Tennant will star in three specials in November 2023 to commemorate the show’s 60th anniversary, before regenerating into the Fifteenth Doctor.

** The first incarnation to be played by the same actor as another incarnation, with the Thirteen Doctor having mysteriously regenerated into this familiar form at the end of [[Recap/DoctorWho2022CENThePowerOfTheDoctor "The Power of the Doctor"]]. Tennant will star in three specials in November 2023 to commemorate the show’s 60th anniversary, before regenerating into the Fifteenth Doctor.

** The first incarnation to be played by the same actor as another incarnation, with the Thirteen Doctor having mysteriously regenerated into this familiar form at the end of [[Recap/DoctorWho2022CENThePowerOfTheDoctor "The Power of the Doctor"]]. Tennant will star in three specials in 2023, before regenerating into the Fifteenth Doctor.

* [[spoiler: David Tennant]] (Fourteenth Doctor, 2022-2023)
** [[spoiler: The first incarnation to be played by the same actor as another incarnation, with the Thirteen Doctor having mysteriously regenerated into this familiar form at the end of [[Recap/DoctorWho2022CENThePowerOfTheDoctor "The Power of the Doctor"]]. Tennant will star in three specials in 2023, before regenerating into the Fifteenth Doctor.]]

* Creator/JodieWhittaker (Thirteenth Doctor, 2017-present)

* Creator/NcutiGatwa (Fourteenth Doctor, starting in 2023)

* K9's voice actor changed in Season 17 from Creator/JohnLeeson, the person most associated with the role (he's still voicing the character to this day), to David Brierley. This was explained on-screen by K9 having "robot laryngitis" during the first story of Season 17 (and thus not having to speak or take part) and the Doctor not quite repairing him correctly until the next season. In-verse, the Doctor left K9 with companions who were parting company with him on a couple of occasions, unpacking a new copy of the robot dog for himself each time. Presumably he downloaded the previous K9's memories and personality into the new housing to ensure it remained "his" dog. A heavily-modified version of K9 also featured in the spinoff ''Series/{{K9}}''.

* James Dreyfus played an earlier, pre-Delgado incarnation of the Master, contemporary to the First and Second Doctors in Big Finish audio dramas.

** The first main black incarnation of the Doctor; Creator/ColinSalmon's Doctor Moon was a minor character who was only confirmed to be the Doctor via WordOfGod, while Creator/JoMartin's Fugitive was part of Thirteen's cast.

* Rassilon, the ruthless and egomaniacal founder of Time Lord society, has been played by five actors: Richard Mathews in [[Recap/DoctorWho20thASTheFiveDoctors "The Five Doctors"]], Creator/TimothyDalton in [[Recap/DoctorWhoS30E17E18TheEndOfTime "The End of Time"]] and Donald Sumpter in [[Recap/DoctorWhoS35E12HellBent "Hell Bent"]], while Big Finish adds Don Warrington, Terrence Hardiman and Creator/RichardArmitage to the mix, chronologically following Mathews but preceeding Dalton.

* Original to Big Finish, CardinalOllistra (Jacqueline Pearce) features in stories set during the Time War. ''The Side of the Angels'' introduced her predecessor (Carolyn Pickles), who had regenerated before the war. Pearce passed away in 2018, but the Carolyn Pickles incarnation was eventually reintroduced to the Time War beginning in 2022, the explanation being that this past Ollistra was recreated from the Matrix supercomputer (essentially the sum of all Time Lord memory) to work in Gallifrey's War Room whilst the current Ollistra led operations off-world.

* Rassilon, the ruthless and egomaniacal founder of Time Lord society, has been played by five actors: Richard Mathews in [[Recap/DoctorWho20thASTheFiveDoctors "The Five Doctors"]], Creator/TimothyDalton in [[Recap/DoctorWhoS30E17E18TheEndOfTime "The End of Time"]] and Donald Sumpter in [[Recap/DoctorWhoS35E12HellBent "Hell Bent"]], while Big Finish adds both Don Warrington and Creator/RichardArmitage to the mix, chronologically following Mathews but preceeding Dalton.

* Romana regenerated from Creator/MaryTamm into Creator/LallaWard — who, confusingly enough, had appeared alongside Tamm in a serial just before she took over the role. This got explained by Romana liking Princess Astra's appearance so much that she decided to regenerate into a double of her. During the regeneration sequence, several uncredited actresses portrays "in-between" versions of Romana as she tries out different bodies, something not portrayed on screen since. A third Romana, played by Juliet Landau, was introduced in the EU audio dramas in 2013; she is said to be a future incarnation, possibly from thousands of years into the future, so it's not known how many Romanas existed before her.

* The non-dramatic parts of the Expanded Universe have introduced a few versions of regenerated Time Lord characters who were never played by any real actor. The ''Literature/DoctorWhoNewAdventures'' featured a new version of the Master [[ComicBookFantasyCasting physically based]] on Creator/BasilRathbone, the ''Literature/EighthDoctorAdventures'' introduced an antagonistic third incarnation of Romana physically based on Louise Brooks, the ''Literature/PastDoctorAdventures'' had a brief appearance from a dark-skinned future incarnation of Romana in [[spoiler:''Tomb of Valdemar'']], the ''Literature/DoctorWhoNovelisations'' had Clive show Rose two original incarnations of the Doctor on top of the official ones, one a tall, bald black woman, the other an [[AmbiguousGender androgynous]] child in a hi-tech wheelchair with a robot dog, in the novelisation of ''Rose'', the ''Magazine/DoctorWhoMagazine'' comic strips featured a unique version of the Master during the Eighth Doctor's era, who was black in human ethnic terms, and featured an incarnation of Rassilon preceding all those on-screen, an older dark-skinned woman, for their tie-in to the ''Time Lord Victorious'' multi-platform event, "Monstrous Beauty", and the ''ComicBook/DoctorWhoTitan'' Eleventh Doctor comics featured an East-Asian-looking boy War Master who accompanied the War Doctor for a time during the Time War, and has occasionally made appearances in other Titan comics.

** The first main black incarnation of the Doctor, Creator/JoMartin's Fugitive having been part of Thirteenth's cast.

* Creator/ColinSalmon as Doctor Moon in [[Recap/DoctorWhoS30E8SilenceInTheLibrary "Silence in the Library"]]/[[Recap/DoctorWhoS30E9ForestOfTheDead "Forest of the Dead"]], a virtual representation of a future incarnation of the Doctor who acts as Charlotte's therapist. Doctor Moon is never stated on-screen to be the Doctor, but Creator/StevenMoffat intended him as such, confirming it in a 2008 email exchange with Creator/RussellTDavies and publicly in 2020.

* [[Recap/DoctorWhoS38E5FugitiveOfTheJudoon "Fugitive of the Judoon"]] introduces Creator/JoMartin as an incarnation of the Doctor whose position in the timeline is unknown, as neither she nor Thirteen remember ever being each other. She's also the first-ever non-white incarnation of the Doctor. [[spoiler:After the events of "The Timeless Children", she's likely a past incarnation who worked for [[NoSuchAgency the Division]].]]

* Creator/MichaelJayston as the Valeyard, allegedly a [[FutureMeScaresMe potential evil future incarnation]] of the Doctor or undesired side effect [[EnemyWithout born out]] of the Doctor, in 1986's ''The Trial of a Time Lord'' (Season 23) and some spin-off Big Finish media.

Every time the Doctor regenerates, the character undergoes a radical change in characterization, costume, and personality. However, all memories and past experiences of past incarnations remain, along with a certain amount of character stability (they're always going to be quirky and altruistic and fight evil aliens), meaning the Thirteenth Doctor is the exact same person as the First Doctor. Personality is a combination of "nature" and "nurture" — one story said that "Although the aspects of their personality caused by "nurture" would not change, the "nature" contribution to their personality would." The mechanic was implemented back when Creator/WilliamHartnell was playing the First Doctor, and obviously growing too ill to carry on further (plus he wasn't getting along with the current producers and in fact had nearly been fired a couple of times over the preceding year). A decision was made to let him retire and bring in Creator/PatrickTroughton for the role, and the writers decided that since the Doctor is an alien, he could change form into a new body if his current one was giving out. From there, the plot device has been modified into the go-to response for any actor wanting to depart from the role of the Doctor — kill off the current incarnation and regenerate them into the next actor, never invoking TheOtherDarrin.

* Creator/DavidBradley (portrayed William Hartnell and Hartnell in-character as the First Doctor) in the 2013 docudrama ''Film/AnAdventureInSpaceAndTime''. He reprised the role within the show's canon for the 2017 Christmas Special, [[Recap/DoctorWho2017CSTwiceUponATime "Twice Upon a Time"]], and has subsequently voiced the First Doctor in Big Finish audios.

* RealLifeWritesThePlot in the case of the Rani; Creator/KateOMara played the original Rani but passed away suddenly in 2014, causing ActorExistenceFailure before returning for a Big Finish audio; her wishes were for someone else to take on the role and the Rani regenerated, with Siobhan Redmond as the new incarnation.

* Creator/JodieWhittaker (Thirteenth Doctor, 2017-22)

** The first black incarnation of the Doctor in the series.

** Jon Culshaw as a stand-in for Tom Baker, due to his uncanny impersonation of the actor's voice. Periodically cast in Big Finish audios, and also played the "real life" Tom Baker in a 50th anniversary spoof.

* Creator/DavidBradley (portrayed William Hartnell and Hartnell in-character as the First Doctor) in the 2013 docudrama ''Film/AnAdventureInSpaceAndTime''. He reprised the role within the show's canon for the 2017 Christmas Special, [[Recap/DoctorWho2017CSTwiceUponATime "Twice Upon a Time"]], and subsequently voices the First Doctor in Big Finish audios.

* The non-dramatic parts of the Expanded Universe have introduced a few versions of regenerated Time Lord characters who were never played by any real actor. The ''Literature/DoctorWhoNewAdventures'' featured a new version of the Master [[ComicBookFantasyCasting physically based]] on Creator/BasilRathbone, the ''Literature/EighthDoctorAdventures'' introduced an antagonistic third incarnation of Romana physically based on Louise Brooks, the ''Literature/PastDoctorAdventures'' had a brief appearance from a dark-skinned future incarnation of Romana in [[spoiler:''Tomb of Valdemar'']], the ''Literature/DoctorWhoNovelisations'' had Clive show Rose two original incarnations of the Doctor on top of the official ones, one a tall, bald black woman, the other an [[AmbiguousGender androgynous]] child in a hi-tech wheelchair with a robot dog, in the novelisation of ''Rose'', the ''Magazine/DoctorWhoMagazine'' comic strips featured a unique version of the Master during the Eighth Doctor's era, who was black in human ethnic terms, and the ''ComicBook/DoctorWhoTitan'' Eleventh Doctor comics featured an East-Asian-looking boy War Master who accompanied the War Doctor for a time during the Time War.

* Ncuti Gatwa (Fourteenth Doctor, starting in 2023)

* Creator/JodieWhittaker (Thirteenth Doctor, 2017-present)

This is the page for TheNthDoctor in its trope-naming and trope-codifying franchise.

* RealLifeWritesThePlot in the case of the Rani; Kate O'Mara played the original Rani but passed away suddenly in 2014, causing ActorExistenceFailure before returning for a Big Finish audio; her wishes were for someone else to take on the role and the Rani regenerated, with Siobhan Redmond as the new incarnation.

** Given River's more successful in utero BioAugmentation (with a little help from the TARDIS), one interpretation is that, had Donna been young enough or met other energy-state criteria, she could have adapted and gone whole-hog. But, Ten had a well-established habit of dithering with the whole process, from clones, to Donna, to his own regeneration, so could well have utterly borked it. It would certainly explain the crushing guilt the Doctor still carries over wiping her.

* K9's voice actor changed in Season 17 from John Leeson, the person most associated with the role (he's still voicing the character to this day), to David Brierley. This was explained on-screen by K9 having "robot laryngitis" during the first story of Season 17 (and thus not having to speak or take part) and the Doctor not quite repairing him correctly until the next season. In-verse, the Doctor left K9 with companions who were parting company with him on a couple of occasions, unpacking a new copy of the robot dog for himself each time. Presumably he downloaded the previous K9's memories and personality into the new housing to ensure it remained "his" dog. A heavily-modified version of K9 also featured in the spinoff ''Series/{{K9}}''.

Every time the Doctor regenerates, the character undergoes a radical change in characterization, costume, and personality. However, all memories and past experiences of past incarnations remain, along with a certain amount of character stability (they're always going to be quirky and altruistic and fight evil aliens), meaning the Thirteenth Doctor is the exact same person as the First Doctor. Personality is a combination of "nature" and "nurture" — one story said that "Although the aspects of their personality caused by "nurture" would not change, the "nature" contribution to their personality would." The mechanic was implemented back when William Hartnell was playing the First Doctor, and obviously growing too ill to carry on further (plus he wasn't getting along with the current producers and in fact had nearly been fired a couple of times over the preceding year). A decision was made to let him retire and bring in Patrick Troughton for the role, and the writers decided that since the Doctor is an alien, he could change form into a new body if his current one was giving out. From there, the plot device has been modified into the go-to response for any actor wanting to depart from the role of the Doctor — kill off the current incarnation and regenerate them into the next actor, never invoking TheOtherDarrin.

* William Russell, who played day-one companion Ian Chesterton in the classic series, voices the First Doctor in a number of Big Finish audios.
* Frazer Hines, who played companion Jamie [=McCrimmon=] in the classic series, voiced the Second Doctor in the Big Finish audio "The Light at the End".
* Patrick Troughton's sound-a-like son, David, has also portrayed his father's Doctor in a few audio dramas.

Though he's been shown to explicitly regenerate only once onscreen (two other times, he's just stolen bodies of other people), twelve people have played the Master so far.

* This wasn't the first time Big Finish had created a new incarnation of a Time Lord due to the death of the original actor — a number of audios feature Graeme Garden and Rufus Hound as later incarnations of the Monk, replacing the long-dead Peter Butterworth.

* Rassilon, the ruthless and egomaniacal founder of Time Lord society, has been played by four actors: Richard Mathews in [[Recap/DoctorWho20thASTheFiveDoctors "The Five Doctors"]], Creator/TimothyDalton in [[Recap/DoctorWhoS30E17E18TheEndOfTime "The End of Time"]], Donald Sumpter in [[Recap/DoctorWhoS35E12HellBent "Hell Bent"]] and Don Warrington in several Big Finish audios.