The Doctor and Susan's escape from Gallifrey
For many pressing reasons, (TV: Twice Upon a Time; AUDIO: Nightshade) the Doctor took a TARDIS (TV: The War Games) and fled his home planet with his granddaughter, Susan Foreman. (TV: An Unearthly Child)
While some accounts suggested the Doctor and Susan were humans, with the planet they escaped from existing in the 49th century, (TV: The Sensorites, PROSE: Doctor Who in an Exciting Adventure with the Daleks, Unnatural History, et al.) the most commonly accepted version of the Doctor and Susan's escape was that their homeworld was Gallifrey and that they flew off in a stolen Type 40 TARDIS. (TV: The War Games, The Name of the Doctor, etc.)
History
The escape
Reasons
Although the First Doctor initially told Ian Chesterton and Barbara Wright that he and Susan were "exiles" from their home planet, (TV: An Unearthly Child) most accounts suggested that this was a figure of speech and they had left of their own accord, albeit possibly as a way of escaping from dangerous circumstances. (TV: The War Games, Twice Upon a Time, AUDIO: Disassembled, etc.)
A boy from Faction Paradox told the Eighth Doctor that he had started out as a 49th century human, who had to leave their home planet to escape from the Enemy. The Enemy subsequently kept rewriting their past until they remembered having been a Time Lord from Gallifrey. (PROSE: Unnatural History)
The Doctor's most common explanation as to why they left Gallifrey was that "[he] was bored". (TV: The War Games) However, a confession to the Veil suggests this was a lie, or at least not the whole truth, (TV: Heaven Sent) with Davros once confronting the Twelfth Doctor about how "no one [ran] the way [the Doctor] [had] [ran] for so small a reason". (TV: The Witch's Familiar) Indeed, the First Doctor did admit to a glass avatar of Bill Potts that there were "many pressing reasons" for his departure from Gallifrey, (TV: Twice Upon a Time) something that the Fourth Doctor would later alluded to when describing his theft of the TARDIS to Adric. (TV: Logopolis)
According to Ashildr, when he was "barely more than a child", the Doctor learned of a prophesied warrior called "the Hybrid" from the Cloister Wraiths and the story made him "so scared" (TV: Hell Bent) that he eventually left Gallifrey out of fear. (TV: Heaven Sent) Another reason he left was because he was curious (COMIC: Return of the Daleks) as to how "good prevail[ed]" over "evil" in the universe; (TV: Twice Upon a Time; AUDIO: The Stones of Venice) according to the Doctor, uncovering this explanation was not the only reason he ran from the planet, but it was what he was running to. (TV: Twice Upon a Time) Another account also stated the Doctor had left during "dark times when [their] world tottered on the edge of ruin, where the impotence of [their] own people had driven him to leave". (PROSE: Roses)
As the Fifth Doctor told Tegan Jovanka, his travels all started when he "deliberately [chose] to go on the run from [his] own people in a rackety old TARDIS". (TV: The Five Doctors) The Fifth Doctor also claimed to have left Gallifrey to find "the ideal society", (PROSE: Cold Fusion) with the Eighth Doctor claiming to have left his planet because he "disagreed with the philosophy of its Masters", (PROSE: Beltempest) and the Second Doctor admitting to leaving due to "the deviousness and corruption of Time Lord politics". (PROSE: World Game) Gideon Crane, a human temporarily fused with the Eighth Doctor's memories, stated that the Doctor left Gallifrey due to "some misplaced revolutionary fervor". (AUDIO: Minuet in Hell)
According to the Decayed Master, the Doctor left Gallifrey on a whim because an unlocked TARDIS was nearby, (AUDIO: The Light at the End) while Clara Oswald told Robin Hood that the Doctor "was moved to steal a TARDIS [and] fly among the stars, fighting the good fight" because he "[found] the plight of the oppressed and weak too much to bear", something the Twelfth Doctor did not dispute. (TV: Robot of Sherwood) The Doctor grew a bond with that TARDIS, describing it as "the most beautiful thing [he] ever saw" upon first entering it, (TV: The Doctor's Wife) after stealing it from a TARDIS repair shop at the Boulevard of Grand Milieu. (PROSE: Celestial Intervention - A Gallifreyan Noir) When confronted with his first TARDIS, the Fifth Doctor would claim he had no time to pick and choose, and had needed to find the first TARDIS he could "lay his hands on". (AUDIO: Prisoners of Fate)
The Doctor also took the Hand of Omega, (TV: Remembrance of the Daleks) some validium, and Gallifrey's moon when he left, (PROSE: A Brief History of Time Lords) and brought Susan with him, either as an accidental passenger (AUDIO: Here There Be Monsters) or on purpose, (AUDIO: The Beginning) having decided it was best to do so to prevent her from being brainwashed and regimented in the thought patterns of the Time Lords. (PROSE: Legacy of the Daleks) He also took his signet ring with him, using it to breach the "laws and barriers" to enable his escape. (PROSE: The Three Paths)
Susan once stated that the Doctor had never explained to her why they needed to leave, simply that they had needed to flee. Still, she reflected that she was no longer comfortable with calling Gallifrey her home at this point. (AUDIO: The Beginning)
According to at least one account, the Doctor, after so much travel, may have already forgotten their original purpose in setting out on their journey as early as in their first incarnation. (PROSE: Who is Dr Who?)
Conflicting stories
By Iris Wildthyme's recollection, the First Doctor's hair was "not even white yet", and even still "a bit of a bruiser", when he left Gallifrey and began his wanderings. (PROSE: The Scarlet Empress)
One account says that the First Doctor rescued Susan from Chancellery Guards shortly after her natural birth, along with her grandmother, Patience, since only the Loom-born were allowed in Gallifrey. The Doctor told Patience he would take their grandchild "far from this world of vampires and valeyards". (PROSE: Cold Fusion)
In an account presented by the Tremas Master, the Doctor existed during a period of civil unrest on Gallifrey, when many students of the Time Lord Academy, led by the Master, revolted against the corrupt Lord President Pundat the Third, and attempted to convince the Doctor to take the position as President, but he decided not to interfere with the current constitution. When Pundat died of stress soon after the revolt, his chosen successor was Chancellor Slann. The students had found the last of Lord Rassilon's descendants, Lady Larn, a seven-year-old child adopted by Councillor Brolin, and decided on a second coup. However, their attempt to convince the Doctor to participate in another coup was overheard and reported to Slann, and the students were "brutally put down" by the Citadel guards, though the Doctor was too highly respected to be terminated, so it was decided to wipe his memory. Bloody reprisals against the students followed, and the Doctor decided to leave Gallifrey in a TARDIS. As it happened, Lady Larn was hiding in the same TARDIS that the Doctor stole, and affectionately called him "grandfather". (PROSE: Birth of a Renegade)
In an account which gave few other details on the event, the Doctor only made it inside the TARDIS because a guard's staser jammed at a crucial moment. God claimed that he had been responsible for this stroke of luck, knowing that the Doctor would need to be alive and roaming the universe to play his part in the quest for the Key to Time in his fourth incarnation. (PROSE: Power to the People)
A second account had the Doctor and Susan already on Gallifrey, fleeing to keep the Hand of Omega safe from those who would misuse it and running straight towards the TARDIS with no hesitation. (COMIC: Time & Time Again)
An account from an Astral Projection of the Doctor's life depicted the Doctor living as a lowly Scrutationary Archivist of the Bureau of Possible Events. He had been disowned and banished from his home by his family in the House of Lungbarrow. In order to replace the disowned Doctor, his family illegally loomed another cousin, Owis. Upon learning of this crime, the Doctor reported his family to the Prydonian Chapter. After an encounter with his gloating Cousin Glospin, Glospin revealed that there was genetic evidence to suggest that the Doctor didn't originally come from the Lungbarrow Loom, having originally been naturally born. Glospin claimed that the Doctor had infiltrated the family, and intended to use his evidence to get the Doctor executed for Loom-jumping.
Glospin attacked the Doctor, obtaining a sample of his DNA, allowing him to frame the Doctor for the murder of their House Kithriarch, Quences. During the fight between the two, the Hand of Omega arrived to attack Glospin, giving the Doctor the opportunity to escape. Knowing Glospin's claims could lead to his execution, the Doctor left Gallifrey, declining the chance to take a Type 53 TARDIS in the process. He instead chose to leave in a Type 40 TARDIS with the Hand of Omega. The Hand piloted the TARDIS to the Dark Time on Gallifrey to collect the granddaughter of the Other, who recognised the Doctor as the reincarnation of the Other, and the two left Gallifrey together in the TARDIS. (PROSE: Lungbarrow)
When the Eighth Doctor recalled his departure from Gallifrey while recovering from amnesia, the First Doctor was shown angrily striding down the corridors of the Capitol after a meeting in the Council Chamber. He found a TARDIS deep beneath the Capitol, and just as he was about to close the door behind him, heard Susan telling him she was coming with him. Shortly after remembering these events, the Eighth Doctor confronted the First Doctor about his motives for leaving Gallifrey, accusing him of having decided to do so in a fit of pique because his fellow Council members could no longer tolerate his arrogance, and had told him as much. Somewhat conflicting with his earlier recollection, he further berated the First Doctor for having chosen to take Susan with him due to thinking her company might be pleasant without considering the consequence for the young girl. (PROSE: The Eight Doctors)
Another account suggested that the Doctor broke the Time Lords' law on non-interference and faced being erased from history by his brother Braxiatel on the order of Lord President Pandad VII. Braxiatel allowed the Doctor and Susan to run, giving him the chance to steal a Type 40 TARDIS and escape Gallifrey. (AUDIO: Disassembled)
One account showed the Doctor, already with Susan and already wearing Victorian era clothing, ready to steal a faulty TARDIS in a repair shop on Gallifrey. (TV: The Name of the Doctor) The Doctor had brought the flying trunk containing the Hand of Omega with him and Susan had brought basic luggage from her house. Armed guards chased the fugitive Doctor and Susan into the repair shop, where the only place for them to hide was a line of TARDISes. Susan walked into one TARDIS, but the Doctor didn't follow her inside, (AUDIO: The Beginning) as he was being advised by a version of Clara Oswald to steal the Type 40 with the faulty navigation system instead of the one Susan had walked inside, as it would be much more fun. (TV: The Name of the Doctor) The Doctor speculated that the TARDIS was deregistered, and that was how it slipped through Gallifrey's transduction barrier and how they evaded the Time Lords. (AUDIO: The Beginning)
One account showed the Doctor enter the TARDIS by himself and, after admiring the interior, found that the ship had no owner. He then took the TARDIS from Gallifrey to explore the universe. (PROSE: Something Borrowed, Something Blue)
The Dalek Combat Training Manual suggested that the Celestial Intervention Agency had coerced the Doctor into taking the Hand of Omega with him when he left Gallifrey. The Doctor placed the Hand on Earth in the 20th century, aware that the Daleks would one day come to steal it in the hope of harnessing its great power. Accordingly, he pre-programmed the Hand to act against Dalek interests. Ultimately, the Doctor's scheme was delayed when he unexpectedly left the planet Earth, and a memory bomb concealed in his TARDIS control console wiped his mind of knowledge of both the Daleks and the Hand of Omega as insurance against his plan being discovered. (PROSE: Dalek Combat Training Manual) As a result, the Doctor was unfamiliar with the Daleks until he encountered them on Skaro. (TV: The Daleks)
The Doctor's memory of the plan itself would not resurface until his seventh incarnation, who would return to Earth to execute it. (TV: Remembrance of the Daleks, PROSE: Dalek Combat Training Manual) Other accounts held that the Doctor truthfully was completely unaware of the Daleks until meeting them on Skaro, (TV: Into the Dalek, et. al) meaning he would have had to hide the Hand for other reasons. (TV: Remembrance of the Daleks, et. al) The Master and the Rani also said the Celestial Intervention Agency had no idea who the Doctor was. (PROSE: Celestial Intervention - A Gallifreyan Noir) Nonetheless, by his seventh incarnation, the Doctor indeed had realised the Daleks would seek the Hand. (TV: Remembrance of the Daleks, et. al)
First flight
Now cut off from his home planet "without friends or protection", the exiled Doctor intended for him and Susan to someday return, (TV: An Unearthly Child) but he deep down knew that they could not. (TV: The Massacre) When he left Gallifrey, the Doctor lost his right to have his mind absorbed into the APC Net at the time of his death (PROSE: Original Sin) and, according to Clara, his "Prydonian privileges were [also] revoked when [he] stole a time capsule and ran away". (TV: Death in Heaven)
According to one account, the first flight of the TARDIS involved the Doctor pulling a lever which turned the TARDIS into a time-travelling machine. During early flights, he would have test instruments connected to the ship to calibrate the controls. (COMIC: Timeslip)
According to another account, immediately after leaving Gallifrey, the Doctor rested in the TARDIS console room, while Susan explored their new home. She found a full-length mirror and saw a pale-skinned fanged figure who vanished after telling her that she was not "the one". The Doctor theorised that, since they were now travelling through time, she encountered a brief echo of either the future or the past. (PROSE: The Exiles)
According to a third account, Susan collapsed in the TARDIS shortly after the engines were stabilised. The Doctor tended to Susan as she slept, and used his jacket as a makeshift pillow for her before she reawakened. Susan then explored the TARDIS as the Doctor tended to the ship's controls. She tripped over a rigger's work case and brought it back to the Doctor when the TARDIS had run out of power. Inside the work case, the Doctor found an artron cell and attached it to the drive system to power an emergency landing. After finding a nearby world, the TARDIS appeared to take over and brought them to the Moon of Earth. (AUDIO: The Beginning)
First destination
Iwa
According to one account, the Time Lord met humans for the first time on the planet Iwa when he and his granddaughter were separated. In his search for his granddaughter, the Time Lord found a human medical colony. The principal work of the facility, called "the Refuge", was to rehabilitate patients identified as "Future Deviants". By undergoing dream therapy, it was hoped that such individuals would not become criminals. The Time Lord soon learned the residents were besieged by fox-like aliens who could disintegrate and reconstitute their bodies. Taking him inside their compound, the humans stripped him of his clothes and burned them, citing possible contamination by the "foxes". They gave him new clothes drawn from their own supply. This meant that he was now wearing the garb of a doctor. When they assumed that he was sent from Earth to help them, he agreed. Not wishing to give them his real name, he referenced his new clothes to derive a title: "the Doctor". The Time Lord assumed this alias because he described it as an honourable profession amongst his own people.
He agreed to help them with their "fox problem" if they would help him find his granddaughter. They discovered she had become trapped in the colonists' "dream chambers", medical devices that put patients into a deep sleep and linked them in one communal dream. Inside the dream chamber, the Doctor's granddaughter met a human colonist named Jill, who promptly gave the young girl the name "Susan", after Jill's own mother. Eventually, the newly named Doctor and Susan were reunited. They helped the colonists broker an uneasy peace with the foxes. They left the colony, deciding to retain the names they had gained there. The Doctor was deeply impressed by humans during this initial encounter. He told Susan they should find a way to settle amongst them for a while so that he could study them and they could maintain a low profile on the run from the Time Lords. (PROSE: Frayed)
The Earth's Moon
In a different account, the Doctor and Susan's first destination was a vivarium beneath the surface of the Moon. Before walking outside, they were confronted by Quadrigger Stoyn, who had become an unwitting passenger and had part of his face burned when the TARDIS took off. Stoyn's job was to take apart the TARDIS' engines before it was sent to be vaporised, but the TARDIS had run out of power, stranding them. The Doctor took the dematerialisation circuit so Stoyn wouldn't leave them behind and they explored the strange location. The Doctor, Susan and Stoyn realised they were in a massive cavern filled with vivariums carefully-preserved specimens. The Archaeons had been seeding primitive planets such as the Earth with life by firing red lightning from the Moon, creating an established order out of the chaos and nurturing the early life forms under controlled conditions.
While checking to see if the TARDIS was a threat, the Archaeons began taking it apart. They took the TARDIS' temporal stasis capacitor while it was still attached to the power source. This caused the stasis field to breach, freezing the Doctor, Susan, Stoyn and the Archaeons in time, allowing the TARDIS to recharge itself. 450 million years later, humans had evolved on the Earth until they established a lunar colony, Giant Leap Base. A group of humans from Giant Leap Base broke the stasis field, taking the Doctor and Susan on board their lunar rover, where they came to. According to this account, the Doctor and Susan learnt about the Earth's history through a "first contact induction video" Susan had been provided while on board the rover.
With the dematerialisation circuit still in the Doctor's possession, the Archaeons had sent nematodes, which didn't affect the Time Lords, to kill all of the humans on the rover. When the Archaeons found the life they had "seeded" had become disorderly and "run rampant", no longer matching their carefully-planned vision, they "purged" the humans on the lunar base and on the Earth with lightning. The Doctor, who was blamed for the disruption of the Archaeons' experiments, was brought back to the cavern. Meanwhile, the humans retaliated against the Archaeons with missiles. After the Doctor went inside the TARDIS, evading the distracted Archaeons, Stoyn tried taking Susan with him, but she refused and ran inside the TARDIS. With the dematerialisation circuit in place, the Doctor and Susan left without Stoyn, as the Doctor felt that he was just as willing to abandon them. Another barrage of missiles breached the atmosphere of the Archaeons' cavern, destroying their weaponry; the Archaeons were pulled outside, though Susan saw Stoyn struggle to reach the rover. Afterwards, the Doctor continuously watched the video about the Earth's history and evolution inside the TARDIS, marvelling at the planet's abundance. (AUDIO: The Beginning)
Other accounts
The Seventh Doctor once told Ace that he had first visited Earth 25 years prior to Ace's present, 1988. (TV: Untitled)
Aftermath on Gallifrey
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Angry, the Doctor's original TARDIS hired a Celestial Intervention Agency agent named Maris to locate the Doctor. Meanwhile, the Master and the Rani learned of the Doctor's escape and became desperate to figure out where he had gone. (PROSE: Celestial Intervention - A Gallifreyan Noir)
In one account of the Second Doctor's trial, the President of the Court told the Doctor that his prolonged and temporal interference drew attention to the very existence of the Time Lords and that the safety of their race had lain in silence and secrecy for many years. He went to surmise that offences of this nature were capital crimes, in comparison to which his theft of the TARDIS was a relatively minor offence, before reluctantly sentencing him to death. The charges were commuted to a period of exile after the Doctor struck a deal with Sardon and agreed to work for the CIA. (PROSE: World Game)
Alternate timelines
A Faction Paradox boy suggested that the very first palimpsest history had been one where the Doctor was a human from a planet in the 49th century, fleeing from an Enemy who'd overrun his home. The boy suggested that the Enemy had overwritten this history when the Doctor wasn't looking, creating new universes where he'd always been a Time Lord, and eventually ones where he'd always been half human. (PROSE: Unnatural History)
Parallel universes
In one universe, an unknown Time Lord, whom the Doctor attended the Academy with, was annoyed when the Doctor stole a TARDIS and escaped Gallifrey. (AUDIO: Exile)
Behind the scenes
Information from invalid sources
In the short story NOTVALID: TARDIS Stolen!, the Gallifrey Gazette investigated the circumstances of the Doctor's theft of the TARDIS and flight from Gallifrey.