Time Lord/Other realities

Versions of Time Lord civilisation existed in many other realities than the Doctor's universe.

Palimpsest universes
As the Doctor's reality was constantly being overwritten, it was an amalgamation of past and future palimpsest universes. Among them, there were an infinite number of possible versions of Time Lord history, but in every single reality, Omega became trapped in the anti-matter universe.

After the Disappearance of Omega, Omega found the anti-matter universe allowed him to watch the rewriting and overwriting of history from a neutral vantage point. In every single palimpsest, events still occurred which caused Omega's disappearance, ensuring that he stayed unchanging. Among these palimpsests were one where there was no Rassilon and the Time Lords only had Omega as their founder, (PROSE: The Infinity Doctors) as seemed to be the case during the First Omega Crisis; (TV: The Three Doctors) one where Rassilon still ruled Gallifrey from deep within the Matrix, (PROSE: The Infinity Doctors) as claimed in the Scrolls of Gallifrey (PROSE: The Legacy of Gallifrey) and witnessed by the Fifth (COMIC: The Tides of Time) and Eighth Doctors; (COMIC: The Final Chapter) and one where Rassilon was a woman and Omega's lover, (PROSE: The Infinity Doctors) with a female original incarnation of Rassilon being documented in accounts dealing with the Kotturuh crisis (COMIC: Monstrous Beauty) in contrast to a variety of other accounts where the original Rassilon was male. (PROSE: The Legacy of Gallifrey, COMIC: Star Death) Omega learned to control this overwriting process using the Effect, allowing him to create new histories at will. (PROSE: The Infinity Doctors)

In the Infinity Doctor's reality, the Doctor eventually returned to Gallifrey where he subsequently taught at the Academy and held a position on the High Council. He organised a peace conference between the Sontaran Empire and Rutan Host on Gallifrey. After facing the Effect and confronting Omega, the Doctor resolved to leave Gallifrey once more. (PROSE: The Infinity Doctors)

When Zagreus showed the Eighth Doctor of the positive-time universe the billion alternatives of anti-time, the Doctor wondered which reality was the real one. Zagreus stated that they were "all real and primary to their inhabitants", usually existing separately but sometimes sharing eras or moments in time when they briefly merged or overlapped. These other prime realities included one where the Eighth Doctor visited Oblivion, one where the Eighth Doctor removed his own heart, one where Gallifrey was replaced with a timeless diamond, one where the Time Lords had "terrible mind powers", one where the Time Lords were removed from time, and one where Nestenes nearly destroyed the Earth. (AUDIO: Zagreus) "They are all real, and primary to their inhabitants. In the grand scheme of things it doesn't matter. Who is there to care?  They all exist, occasionally sharing moments and eras, the rest of the time self contained and unaware."

- Zagreus

Ancestor-universe
According to some accounts, the Great Old Ones' universe of origin was a universe which existed before the Doctor's and was destroyed right before the Big Bang (PROSE: All-Consuming Fire) by the Gods of Ragnarok. (PROSE: Divided Loyalties)

The Sixth Doctor asserted, (PROSE: Millennial Rites) as Rassilon had once speculated, (PROSE: Divided Loyalties) that this world had been ruled by beings who were equivalent to the Time Lords of his own universe, and, indeed, called themselves Time Lords as well, although "they were lords of a very strange version of time and space". These "elder gods" developed the "dark science" of quantum mnemonics, which could rewrite the fabric of reality even more powerfully than Block Transfer Computation. They had a military strategist, later known as the Great Intelligence; the Doctor believed Yog-Sothoth to be his "real name", (PROSE: Millennial Rites) although according to one account, the names commonly used for the Great Old Ones were given to them by Rassilon in the Dark Times as brands which gave the new Time Lords power over them, and were not actually their original names in their universe of origin. This later account also posited that the beings which became the Guardians of Time in the Doctor and Rassilon's universe were the "upper echelons" of these Great Old Ones. (PROSE: Divided Loyalties)

As the Doctor recounted: "As their universe reached the point of collapse, a group of these "Time Lords" shunted themselves into a parallel dimension which collapsed seconds after ours. Moments later, they erupted into our universe, and soon discovered that they were in possession of undreamt-of powers. (…) And (…) they decided that since they now had god-like powers, they should behave like gods."

- Sixth Doctor (PROSE: Millennial Rites)

In addition to Yog-Sothoth, the Gods of Ragnarok, and the Guardians, these Great Old Ones who had once been "Time Lords" included Hastur, alias Fenric; Lloigor, alias the Animus of Vortis; Shub-Niggurath; Cthulhu; Melefescent; Tor-Gasukk, Gog and Magog; Nyarlathotep; and Dagon. (PROSE: Millennial Rites, Divided Loyalties) Azathoth was also cited as one of these pre-universal Great Old Ones in an account which generally accorded with this material but did not specify their original nature as the Time Lords of another universe. (PROSE: All-Consuming Fire)

However, the origins of the Great Old Ones or elder gods were disputed. (PROSE: Christmas on a Rational Planet, AUDIO: The Magic Mousetrap, etc.) For example, the Carnival Queen claimed that what the Time Lords thought they knew about the pre-universe were actually fragmentary accounts of the original state of their own realtiy, the world of irrationality and magic which existed before the creation of rationality; this meant that the Great Intelligence and other such surviving "godlings" were natives of that version of reality, and not a previous universe with its own Time Lords. (PROSE: Christmas on a Rational Planet)

Parallel universes
"Forty five billion universes to the left" of the universe of the Doctor's Gallifrey was a universe inhabited by the Word Lords. (AUDIO: The Word Lord) Being that dimension's version of the Time Lords, their society was fueled by the Hand of All instead of the Web of Time or Eye of Harmony. (AUDIO: A Death in the Family)

In Auld Mortality's universe, where the force known as Auld Mortality ran throughout Gallifrey's history, the Doctor became a famous author on Gallifrey and eventually decided to leave in a stolen TARDIS. Quences, possessing the body of Badger after his death, tricked the Doctor into staying within the TARDIS as he'd hoped to make him President of the Time Lords. The Doctor spent years trapped in the TARDIS, during which time his granddaughter Susan was elected President. On the eve of her inauguration, she visited her grandfather and freed him from Quences' influence, letting him leave Gallifrey. (AUDIO: Auld Mortality) The Doctor travelled in time and space, freely rewriting history, eventually forcing President Susan to send an agent, Zeuro, after him to stop his interference. After the Supreme Council learned of the Doctor's actions, Susan was forced to authorise his execution and confronted him herself. Discovering that the Doctor was travelling with a possibility engine generated facsimile of herself, Susan agreed to swap places with the facsimile, who was dying of radiation poisoning. The facsimile returned to Gallifrey to assume the presidency until her death. (AUDIO: A Storm of Angels)

In the Unbound Universe, the Time Lords were the rulers of the universe. (AUDIO: The Library in the Body) The Doctor and the Master both became renegades, with the Doctor eventually being caught by the Time Lords and exiled to Earth in 1997. (AUDIO: Sympathy for the Devil) The Time Lords were wiped out in the Great War, having rejected the Doctor's advice, (AUDIO: Asking for a Friend) leaving the Doctor the only survivor and thus the Ruler of the Universe. (AUDIO: The Library in the Body) The Master later emerged as a second survivor. (AUDIO: The Emporium at the End)

In another parallel universe where the Valeyard had won the trial against the Doctor and gained his regenerations, the Time Lords recruited Melanie Bush to stop his alterations of history. (AUDIO: He Jests at Scars...)

In one parallel universe, the Time Lords pursued the Doctor after she escaped before her exile could be enforced. She was eventually captured and confined to her TARDIS. (AUDIO: Exile)

In one parallel universe, legends said that the Time Lords were annihilated by an alliance of Kaleds and Thals after they had attempted to wipe out the Kaleds while they were still a young species. (AUDIO: Palindrome)

In one reality, the Fourth Doctor destroyed the incubation chamber on the Time Lords' mission to wipe out the Daleks at their creation. This caused huge alterations to time, (AUDIO: Dust Devil) resulting in the creation of the Unified Skaroan Alliance who discovered time travel and waged a time war against the Time Lords. (AUDIO: Aftershocks) Narvin retrieved the mortally-wounded Doctor from Skaro and informed him of the Time War his actions had caused, giving him an elixir so he could regenerate. (AUDIO: Dust Devil) In his new incarnation, now known as the Warrior, he fought in the Time War and eventually became President of the Time Lords. As President he fought off an invasion of Gallifrey by the Kraals. (AUDIO: The Difference Office)

In one parallel universe, the Time Lords were long gone according to River Song. (AUDIO: The Two Rivers)

Artificially created
The Quantum Archangel created a parallel universe where the Doctor was never exiled to Earth by the Time Lords and the War in Heaven began when the Sixth Doctor convinced his people to abandon the non-interference policy to launch a jihad against the Enemy, who were an old foe of his. During the War, the Time Lords created numerous time dreadnoughts and allied with the Cyberlords. The Doctor eventually became Lord President. After the Master betrayed his people by giving Gallifreyan technology to the Enemy, the tide turned against the Time Lords. Before the Enemy could win the War, Lord President Admiral Doctor destroyed the universe using the Armageddon Sapphire. (PROSE: The Quantum Archangel)

Alternate timelines
In an alternate timeline temporarily created by the Black Guardian, the First Doctor never left Gallifrey and instead became the President of the High Council. Because the Doctor never interfered with their history, the Daleks grew to become more powerful than the Time Lords. The Time Lords lived in fear of the Dalek Empire and tried to appease them. (COMIC: Time & Time Again)

In an alternate timeline where the Daleks were peace-loving academics, the Time Lords were on good terms with them, their President having been cured by Dalek surgeons. (PROSE: The Ripple Effect)

In an alternate timeline created by the Sirens of Time, the Knights of Velyshaa conquered Gallifrey. However, the Fifth, Sixth and Seventh Doctors, with the help of the Temperon, averted this. (AUDIO: The Sirens of Time)

In a possible timeline Timothy Dean showed John Smith to prevent him giving the Aubertides the pod containing Time Lord biodata, the Aubertides had conquered Gallifrey. With the power of regeneration they multiplied quickly, and once they went to Gallifrey using the Doctor's TARDIS they took over with sheer force of numbers. A gigantic crystal memorial was constructed for Aphasia. In an attempt to get information about the Matrix Greeneye tortured the President by beginning to cut off her head, but stopping before he could prevent her from regenerating. (PROSE: Human Nature)

During the anti-time crisis, the Eighth Doctor was shown a Matrix projection of Gallifrey if the anti-time corruption was not stopped. In this possible future, President Romana sentenced the Daleks trapped in a time loop to death without care for their importance to the Web of Time. (AUDIO: Neverland)

Numerous alternate versions of Gallifrey were created during the temporal shockwave caused by 's interference in the creation of the Daleks. (AUDIO: Shockwave) After rewriting time completely and conquering the universe with his Daleks, the Master visited Gallifrey and found it home to primitive farmers, deeming them "quite pathetic". This was negated when the Master worked with the Dalek Time Strategist and a parallel universe version of himself to prevent his younger self rewriting time. (AUDIO: He Who Wins)

In an alternate timeline in the Beyond, Gallifrey was attacked by aliens during President Romana's era. Leela was killed during one attack, inspiring the President to order the destruction of the entire Cannavar system to strike back against the enemy. (AUDIO: Beyond)

In an aborted timeline where unleashed an entropy wave, the Time Lords attempted to divert it into another universe with a Charged Vacuum Emboitment. The Master from the Unbound Universe took over Gallifrey and ordered the Time Lords to send every Battle TARDIS above Gallifrey to defend against the coming wave. The Master detonated all the Battle TARDISes, destroying Gallifrey and the Eye of Harmony, however this failed to stop the wave. (AUDIO: Masterful)

Timelines within the Axis
During their travels in the Axis, Romana, Narvin, Leela and Braxiatel discovered numerous alternate versions of Gallifrey which had been cauterised from normal time and encased within the Axis.

These included one Gallifrey where the Time Lords freely sold their technology to the wider universe, (AUDIO: Reborn) another ruled by Imperiatrix Romana where Time Lords intervened ruthlessly in the affairs of other planets, (AUDIO: Disassembled) another where the war against the Vampires had never ended (AUDIO: Annihilation) and finally one where Rassilon had failed to finish the Eye of Harmony before his death so the Gallifreyans had never achieved time travel. Romana, Narvin and Leela settled on this Gallifrey for a time. (AUDIO: Forever, Emancipation, Evolution) The Daleks used the Axis to plunder numerous alternate Gallifreys, including the one they'd settled on, until being stopped by Romana, Narvin and Leela. (AUDIO: Arbitration, Extermination)