The Doctor

The Doctor was a Time Lord from the planet Gallifrey who, as a renegade, fought injustice where he found it. Later, he was believed (or he believed himself) to be the only Time Lord to survive the Last Great Time War with the Daleks. Throughout his life, he had a particular association and affinity with the planet Earth and its Humans.

Biography
The Doctor is not his real name, like The Rani's real name is Ushas, and The Master's is Koschei, and The Monk's Mortimus. He had chosen never to reveal it, except to River Song. It is possible that his name might be Theta Sigma, but he said this was a nickname.
 * ''However He might be saying this to help disguise his real name

Despite the fact that the Doctor was essentially the same person, he has through the Time Lord power of regeneration, changed personality and outer form. The Doctor continues to be a heroic figure, fighting the evils of the universe wherever he finds them, even if his values and motives are sometimes alien to Humankind.

Understood in Gallifreyian society to be one of the forty-five cousins loomed to the House of Lungbarrow, the Doctor responded to their disownership of him by claiming to have "other families" (NA: Lungbarrow). These would somehow seem to include parents (DW: Doctor Who: The TV Movie), children (DW: Fear Her), a granddaughter (DW: An Unearthly Child) and a brother (DW:Smith and Jones, BNA:Tears of the Oracle ). All were (most likely) lost by the conclusion of the Last Great Time War, either killed during that conflict or having died long before it (DW: The Tomb of the Cybermen). As a child the Doctor always wanted to drive a train. (DW: Black Orchid)

The Doctor's stated age has fluctuated wildly, ranging from approximately 450, as stated not long after his first regeneration (DW: The Tomb of the Cybermen), to 1,012 as stated by the Eighth Doctor (EDA: Vampire Science). For reasons unknown, the Ninth Doctor claims to be only 900 years old (DW: Aliens of London) and the Tenth Doctor gives his exact age at one point as 903 (DW: Voyage of the Damned).


 * Even if the novels are discounted, this would appear to contradict the Sixth Doctor claiming to be 900 years old in Revelation of the Daleks and the Seventh Doctor stating his exact age as 953 in Time and the Rani. The series has yet to explain why the Doctor shaved at least 50 years off his age (though likely more since the complete "lifetimes" of both the Seventh and Eighth Doctors must be taken into account).

The Ten Doctors

 * The First Doctor was a somewhat unreadable, guarded figure, irascible, protective of young women who reminded him of his grand-daughter Susan, a brilliant but often short-tempered scientist and a keen strategist. Though far from invulnerable, he usually ran rings around lesser intellects.


 * The Second Doctor was warm and wise, a sort of "cosmic hobo," often as frightened of the alien menaces he faced as those around him. Often overtaken by events, he improvised his way out of trouble. But he also had a manipulative streak about him, too.


 * The Third Doctor cut more of a dashing figure than his predecessors, a dandy with a penchant for gadgets and martial arts, particularly Venusian aikido. His difficult relationship with the Brigadier softened to an easy mutual trust. He had a personal arch-enemy, the Master. Due to his exile by his own people, he spent most of his life on Earth.


 * The Fourth Doctor was something of a cross between Willy Wonka and the Mad Hatter, rarely without his signature scarf of incredible length. He was perhaps the most eccentric incarnation and progressed from bohemian vagabond to manic scatterbrain to a more mature and sombre figure.


 * The Fifth Doctor had a fondness for cricket. He was somewhat more nervous and less sure of himself than the two previous Doctors, though all the more heroic because of it. Like the Second Doctor, he often found himself backed into a corner and had to figure out way back once more.


 * The Sixth Doctor, grandiose and eloquent, sported a multi-hued wardrobe that looked as if designed by Christian Lacroix, had a manic personality and an acerbic wit which could shade into moral passion. He loved a good quote and rarely got caught off-guard by an enemy.


 * The Seventh Doctor, his voice touched by a Scottish burr, combined the vagabond nature of the Second and Fourth Doctors with the scientific brilliance of the First and Third incarnations. Armed with a keenly tactical mind, his personality deepened and darkened. He seemed, often, a demi-god walking amongst lesser beings, letting his companions know little, an avenging angel driven to eradicate evil at any cost.


 * The Eighth Doctor showed a romantic and sensitive side not evident in the previous Doctors. More morally flexible than his predecessor, this Doctor suffered bouts of amnesia, first after his initial regeneration and again after the first destruction of Gallifrey.


 * The Ninth Doctor displayed much of the playfulness of the Fourth and early Seventh Doctors, but also displayed a pragmatism which could at times appear callous. This Doctor also seemed very conscious of the effects his actions had on those around him. His attire was also considerably more conservative and less conspicuous than those of his predecessors and his accent and attitude more working class.


 * The Tenth Doctor's character is manic, that of an eccentric crackpot, a cross between the Fourth Doctor and the Ninth, with hints of the Seventh with the style of the fifth and a fondness for pop cultural reference. He has a serious side, but quite often his other wins out. He can occasionally appear quite ruthless. He has also been noted to be very good looking and unintentionally rude.

Other Doctors
Due to the fluid nature of the time-stream and the existence of parallel realities, other versions of the Doctor have come to light. Following are descriptions of some of those currently known to exist.

Past Doctors

 * During a mindwrestling between the Doctor and Morbius a visual display, showing the previous incarnations of the two Time Lords, seemed to show that the Doctor had at least eight incarnations prior to the first incarnation known to us. (DW: The Brain of Morbius)


 * ''This contradicts the many times the Doctor has stated that he had no incarnations before the first about which we had knowledge and also the knowledge that the number of a Time Lord's cycle of regenerations generally only runs to twelve.


 * Much dispute exists as to the reality of these incarnations. Popular theories says that the Doctor lost the match. Another theory explains that these other faces belonged to Morbius rather than the Doctor. and another explains away these as incarnations of incarnations of the Other (see below).

The Watcher

 * Towards the end of his fourth incarnation, the Doctor, was assisted by a mysterious whiteclad Watcher, a version of himself in between his fourth and fifth imcarnations. (DW: Logopolis).

The Valeyard

 * The Doctors enemy, the Valeyard was revealed to be a potential future Doctor, existing somewhere between his twelfth and final incarnations and embodying the evil of Doctor's dark side. (DW: The Trial of a Time Lord).

Merlin

 * The Doctor discovered evidence of Merlin, a future or alternative version of himself known to Ancelyn and Morgaine. (DW: Battlefield)


 * Possibly the same incarnation as Muldwych.


 * The fourth and fifth incarnations of the Doctor met another Merrlin, a High Evolutionary working with Rassilon in the Matrix. We do not know of a connection, if any, to the other Merlin.

The Other
A Time Lord contemporary with Rassilon and Omega, the Other may have physically died but transferred his essence to the Doctor, living many centuries after him.

This would explain the earlier faces seen while the Doctor mind wrestled Morbius: these belonged to the Other, not the Doctor proper.

Muldwych
A future incarnation of the Doctor, Muldwych spent many hundreds of years stranded on Earth. (NA: Birthright, Happy Endings)


 * Possibly the same incarnation as Merlin.

Dr. Who (Land of Fiction)
The Doctor encountered Dr. Who in the Land of Fiction (NA: Head Games). The nature of Dr. Who seems somewhat unclear and contradictory except that Dr. Who seems to live in a more juvenile and morally simplistic world than the Doctor with villains to match. As the real Doctor has regenerated, so has his counterpart, Dr. Who.

First Doctor

 * In a reality created by the Black Guardian, the Doctor occupies the position of puppet Lord President of Gallifrey, serving the Dalek Empire and sitting idly by as armies of alien invaders squabble over Earth. (DWM: Time & Time Again)

Third Doctor

 * During his trial the Doctor was shown a series of portraits from which he might choose the form of his next regeneration before the Time Lords exiled him to Earth. None was to his liking, nor did any of them look like his third incarnation. (DW: The War Games)


 * One of these potential third incarnations took over Britain as a fascist military dictator. Though not known at the time when the Doctor visited there (DW: Inferno), this was later revealed. (NA: Timewyrm: Revelation, The Face of the Enemy)


 * An Unbound Third Doctor who never joined UNIT as its scientific advisor, but instead met and befriended the Brigadier long after his UNIT heyday, is also known to exist. (DWU: Sympathy for the Devil)


 * The machinations of Faction Paradox created an earlier death on the planet Dust for the Third Doctor than had occurred in the Doctor's established timeline. He still regenerated into the same Fourth Doctor, and almost everything else remained the same, but it created a paradox which left the Eighth Doctor susceptible to Faction Paradox's plans. (EDA/PDA: Interference: Book One, Interference: Book Two)

Fourth Doctor

 * An alternative fourth incarnation, who, having just regenerated, the and his new companions Jenny and Jimmy prevented the Daleks from gaining the Crystal of All Power. (Doctor Who and the Daleks and the Seven Keys to Doomsday)

Eighth Doctor

 * The Doctor's awareness passed through various alternative visions of himself, ranging from Humans to a violent cyborg to talking cartoon cats. (DWM: The Glorious Dead)


 * A version of the Doctor living on Gallifrey, (PDA: The Infinity Doctors).


 * Not strictly speaking, a version of the Doctor's eighth incarnation, this version nevertheless looked identical to him, except that he had short-cropped hair.

Ninth Doctor

 * A melancholic Ninth Doctor, at first reluctantly, fought the Shalka on Earth, and in so doing acquiring a new travelling companion, Alison Cheney (Scream of the Shalka, EDA: The Tomorrow Windows).

Other Versions or Incarnations

 * Apparations of various alternative possibilites from his first through his eighth incarnations appeared to the Seventh Doctor and his companions. (NA: So Vile a Sin).


 * A 1980s-style "contemporary" Doctor, in a Greenpeace t-shirt. (Doctor Who: The Ultimate Adventure).


 * The Doctor and Ace met one of the Doctor's future selves, accompanied by a companion, Ria. (DWM: Party Animals). Later, the Eighth Doctor collapsed and seemingly regenerated (DWM: The Final Chapter) into this incarnation, however, it turned out that he had faked his regeneration in order to defeat the Threshold (DWM: Wormwood)


 * Grandfather Paradox, the patriarch of Faction Paradox, may have his origins as a warped-timeline version of the Doctor. (NA: Christmas on a Rational Planet onwards).


 * ''This association remains speculative. The fact that Grandfather Paradox has only one arm, once suffered exile by the Time Laods now hates them, provides a clue. While exiled on Earth, the Doctor had a serpent tattoo placed there to indicate his exile status. (NA: Christmas on a Rational Planet)


 * He may have cut off arm and begun a vendetta. Also, a Grandfather Paradox indicates a situation where a person uses time travel to kill one of their ancestors. In the Doctor's case, Faction Paradox saw to it that he would die in his third incarnation and never regenrate.''


 * A Doctor who never left Gallifrey. (DWU: Auld Mortality) and then, deciding to do so, changed Earth history, with disastrous results (DWU: ''A Storm of Angels").


 * A Doctor who, while not really evil, is nonetheless far from heroic. This Doctor believes that the ends justify the means. (DWU: ''Full Fathom Five").


 * An alternate reality version of the Valeyard who won his battle with the Doctor (DWU: He Jests at Scars...).


 * An Doctor who turns out to be the fantasy world alter ego of a mentally ill writer recollecting his script for a proposed television series about a science fiction television character tentatively called Doctor Who (DWU: Deadline).


 * The main timeline has a similar fictional television space-time traveller to the character of Doctor Who, known as Professor X.


 * An alcohol-addled female Doctor who has escaped punishment by the Time Lords (DW: The War Games) This story also features appearances by her past male Unbound incarnation. (DW: Exile)


 * Grandfather Halfling. The Halfling in his title refers to his dual nature: half Human, half Gallifreyan. (FP: Of the City of the Saved)


 * Identity heavily implied, but not directly stated.


 * The Doctors in The Curse of Fatal Death: The Ninth Doctor, The (Quite Handsome) Tenth Doctor, The (Shy) Eleventh Doctor, The (Handsome) Twelth Doctor, The (Female) Thirteenth Doctor.


 * Dr. Who, a human scientist who experiences alternate versions of two First Doctor adventures, encountering the Daleks on their homeworld of Skaro (Dr. Who and the Daleks) and again on a futuristic Earth (Daleks - Invasion Earth 2150 AD).

Similar individuals to the Doctor

 * The fictional character Professor X is similar to the Doctor.
 * The Wanderer is also similar to the Doctor.

Orgins of the Other Doctors

 * ''Inferno depicted a fascist alternative England as having a nameless leader who never apepars in person, only on posters. The identitification of this leader as the Doctor came much later, in part to explain why the Doctor did not seem to exist in that world.


 * The past incarnations of the Doctor (or the Other) started as a mischevious joke on the part of the production personnel of Doctor Who, to tweak with established continuity. When shooting The Brain of Morbius, dressed up in costumes to represent earlier versions of the Doctor before the supposed first. The character of the Other originated in a (even to this day) document explaining the Doctor's true origins written up by later script editor Andrew Cartmel with input from a few other Doctor Who writers, some of them fans and well aware of the enigmatic Doctors, who should not exist in established continuity. The Other character originated in the document and got a mention in the novelization of Remembrance of the Daleks. The Other remains a popular way to "repair" the contradict of Doctors before the first one.


 * The "Greenpeace Doctor" appeared when his understudy, David Banks, had to fill in for Jon Pertwee when he felt too ill to perform the main role in the stage play Doctor Who: The Ultimate Adventure.


 * The character of Dr. Who in the series existed as a way to reconicle the more adult world of the Doctor (especially in the novels and other media other than television) with the more lighthearted children's comics versions and with Peter Cushing's Doctor Who.


 * The "future Doctor" and Ria, who met the Seventh Doctor and Ace, both originated from Audio Visuals, fan audio plays produced by Nicholas Briggs and others, in which he played an original version of the Doctor. Later, he returned to Doctor Who Universe as the Doctor's next incarnation in a "stunt" intended to startle and shock fans and to bluff them into thinking they had really replaced the old Doctor for good. They later revealed this Doctor as not the real one. Nicholas Briggs late appeared in BBV audio plays as "Fred", a clear Doctor substitute encountering the "Cyberons" (Cybermen).

Other characters outside the mainstream Doctor Who Universe

 * The BBV character The Stranger, played by Colin Baker, and partnered with "Miss Brown" played by Nicola Bryant and clearly Peri, started off as thinly-veiled version of the Doctor in his sixth incarnation. However, BBV decided with the fourth adventure to explain away the Stranger as a different character with a different past.


 * BBV also featured the adventures of the Professor (later called the Dominie, for legal reasons) played by Sylvester McCoy and Ace (played by Sophie Aldred) (later called Alice), an even more thinly veiled version of the Doctor in his seventh incarnation. Depending on your point of view, you could regard these either as true adventures of the Doctor using an alias or fan fiction using the original actors.